Beispiel #1
0
    def _simple_new(cls, left, right, closed=None, name=None,
                    copy=False, verify_integrity=True):
        result = IntervalMixin.__new__(cls)

        if closed is None:
            closed = 'right'
        left = _ensure_index(left, copy=copy)
        right = _ensure_index(right, copy=copy)

        # coerce dtypes to match if needed
        if is_float_dtype(left) and is_integer_dtype(right):
            right = right.astype(left.dtype)
        if is_float_dtype(right) and is_integer_dtype(left):
            left = left.astype(right.dtype)

        if type(left) != type(right):
            raise ValueError("must not have differing left [{}] "
                             "and right [{}] types".format(
                                 type(left), type(right)))

        if isinstance(left, ABCPeriodIndex):
            raise ValueError("Period dtypes are not supported, "
                             "use a PeriodIndex instead")

        result._left = left
        result._right = right
        result._closed = closed
        result.name = name
        if verify_integrity:
            result._validate()
        result._reset_identity()
        return result
Beispiel #2
0
def nanskew(values, axis=None, skipna=True):
    """ Compute the sample skewness.

    The statistic computed here is the adjusted Fisher-Pearson standardized
    moment coefficient G1. The algorithm computes this coefficient directly
    from the second and third central moment.

    """

    values = _values_from_object(values)
    mask = isna(values)
    if not is_float_dtype(values.dtype):
        values = values.astype('f8')
        count = _get_counts(mask, axis)
    else:
        count = _get_counts(mask, axis, dtype=values.dtype)

    if skipna:
        values = values.copy()
        np.putmask(values, mask, 0)

    mean = values.sum(axis, dtype=np.float64) / count
    if axis is not None:
        mean = np.expand_dims(mean, axis)

    adjusted = values - mean
    if skipna:
        np.putmask(adjusted, mask, 0)
    adjusted2 = adjusted ** 2
    adjusted3 = adjusted2 * adjusted
    m2 = adjusted2.sum(axis, dtype=np.float64)
    m3 = adjusted3.sum(axis, dtype=np.float64)

    # floating point error
    #
    # #18044 in _libs/windows.pyx calc_skew follow this behavior
    # to fix the fperr to treat m2 <1e-14 as zero
    m2 = _zero_out_fperr(m2)
    m3 = _zero_out_fperr(m3)

    with np.errstate(invalid='ignore', divide='ignore'):
        result = (count * (count - 1) ** 0.5 / (count - 2)) * (m3 / m2 ** 1.5)

    dtype = values.dtype
    if is_float_dtype(dtype):
        result = result.astype(dtype)

    if isinstance(result, np.ndarray):
        result = np.where(m2 == 0, 0, result)
        result[count < 3] = np.nan
        return result
    else:
        result = 0 if m2 == 0 else result
        if count < 3:
            return np.nan
        return result
Beispiel #3
0
    def _simple_new(cls, left, right, closed=None,
                    copy=False, dtype=None, verify_integrity=True):
        result = IntervalMixin.__new__(cls)

        closed = closed or 'right'
        left = ensure_index(left, copy=copy)
        right = ensure_index(right, copy=copy)

        if dtype is not None:
            # GH 19262: dtype must be an IntervalDtype to override inferred
            dtype = pandas_dtype(dtype)
            if not is_interval_dtype(dtype):
                msg = 'dtype must be an IntervalDtype, got {dtype}'
                raise TypeError(msg.format(dtype=dtype))
            elif dtype.subtype is not None:
                left = left.astype(dtype.subtype)
                right = right.astype(dtype.subtype)

        # coerce dtypes to match if needed
        if is_float_dtype(left) and is_integer_dtype(right):
            right = right.astype(left.dtype)
        elif is_float_dtype(right) and is_integer_dtype(left):
            left = left.astype(right.dtype)

        if type(left) != type(right):
            msg = ('must not have differing left [{ltype}] and right '
                   '[{rtype}] types')
            raise ValueError(msg.format(ltype=type(left).__name__,
                                        rtype=type(right).__name__))
        elif is_categorical_dtype(left.dtype) or is_string_dtype(left.dtype):
            # GH 19016
            msg = ('category, object, and string subtypes are not supported '
                   'for IntervalArray')
            raise TypeError(msg)
        elif isinstance(left, ABCPeriodIndex):
            msg = 'Period dtypes are not supported, use a PeriodIndex instead'
            raise ValueError(msg)
        elif (isinstance(left, ABCDatetimeIndex) and
                str(left.tz) != str(right.tz)):
            msg = ("left and right must have the same time zone, got "
                   "'{left_tz}' and '{right_tz}'")
            raise ValueError(msg.format(left_tz=left.tz, right_tz=right.tz))

        result._left = left
        result._right = right
        result._closed = closed
        if verify_integrity:
            result._validate()
        return result
Beispiel #4
0
def _isfinite(values):
    if is_datetime_or_timedelta_dtype(values):
        return isna(values)
    if (is_complex_dtype(values) or is_float_dtype(values) or
            is_integer_dtype(values) or is_bool_dtype(values)):
        return ~np.isfinite(values)
    return ~np.isfinite(values.astype('float64'))
Beispiel #5
0
def pad_2d(values, limit=None, mask=None, dtype=None):
    if dtype is None:
        dtype = values.dtype
    _method = None
    if is_float_dtype(values):
        name = 'pad_2d_inplace_{name}'.format(name=dtype.name)
        _method = getattr(algos, name, None)
    elif is_datetime64_dtype(dtype) or is_datetime64tz_dtype(dtype):
        _method = _pad_2d_datetime
    elif is_integer_dtype(values):
        values = ensure_float64(values)
        _method = algos.pad_2d_inplace_float64
    elif values.dtype == np.object_:
        _method = algos.pad_2d_inplace_object

    if _method is None:
        raise ValueError('Invalid dtype for pad_2d [{name}]'
                         .format(name=dtype.name))

    if mask is None:
        mask = isna(values)
    mask = mask.view(np.uint8)

    if np.all(values.shape):
        _method(values, mask, limit=limit)
    else:
        # for test coverage
        pass
    return values
Beispiel #6
0
def backfill_2d(values, limit=None, mask=None, dtype=None):
    if dtype is None:
        dtype = values.dtype
    _method = None
    if is_float_dtype(values):
        _method = getattr(algos, 'backfill_2d_inplace_%s' % dtype.name, None)
    elif is_datetime64_dtype(dtype) or is_datetime64tz_dtype(dtype):
        _method = _backfill_2d_datetime
    elif is_integer_dtype(values):
        values = _ensure_float64(values)
        _method = algos.backfill_2d_inplace_float64
    elif values.dtype == np.object_:
        _method = algos.backfill_2d_inplace_object

    if _method is None:
        raise ValueError('Invalid dtype for backfill_2d [%s]' % dtype.name)

    if mask is None:
        mask = isnull(values)
    mask = mask.view(np.uint8)

    if np.all(values.shape):
        _method(values, mask, limit=limit)
    else:
        # for test coverage
        pass
    return values
Beispiel #7
0
def backfill_1d(values, limit=None, mask=None, dtype=None):
    if dtype is None:
        dtype = values.dtype
    _method = None
    if is_float_dtype(values):
        name = 'backfill_inplace_{name}'.format(name=dtype.name)
        _method = getattr(algos, name, None)
    elif is_datetime64_dtype(dtype) or is_datetime64tz_dtype(dtype):
        _method = _backfill_1d_datetime
    elif is_integer_dtype(values):
        values = ensure_float64(values)
        _method = algos.backfill_inplace_float64
    elif values.dtype == np.object_:
        _method = algos.backfill_inplace_object

    if _method is None:
        raise ValueError('Invalid dtype for backfill_1d [{name}]'
                         .format(name=dtype.name))

    if mask is None:
        mask = isna(values)
    mask = mask.view(np.uint8)

    _method(values, mask, limit=limit)
    return values
Beispiel #8
0
def nansum(values, axis=None, skipna=True, min_count=0, mask=None):
    """
    Sum the elements along an axis ignoring NaNs

    Parameters
    ----------
    values : ndarray[dtype]
    axis: int, optional
    skipna : bool, default True
    min_count: int, default 0
    mask : ndarray[bool], optional
        nan-mask if known

    Returns
    -------
    result : dtype

    Examples
    --------
    >>> import pandas.core.nanops as nanops
    >>> s = pd.Series([1, 2, np.nan])
    >>> nanops.nansum(s)
    3.0
    """
    values, mask, dtype, dtype_max, _ = _get_values(values,
                                                    skipna, 0, mask=mask)
    dtype_sum = dtype_max
    if is_float_dtype(dtype):
        dtype_sum = dtype
    elif is_timedelta64_dtype(dtype):
        dtype_sum = np.float64
    the_sum = values.sum(axis, dtype=dtype_sum)
    the_sum = _maybe_null_out(the_sum, axis, mask, min_count=min_count)

    return _wrap_results(the_sum, dtype)
Beispiel #9
0
    def _simple_new(cls, values, name=None, freq=None, **kwargs):
        """
        Create a new PeriodIndex.

        Parameters
        ----------
        values : PeriodArray, PeriodIndex, Index[int64], ndarray[int64]
            Values that can be converted to a PeriodArray without inference
            or coercion.

        """
        # TODO: raising on floats is tested, but maybe not useful.
        # Should the callers know not to pass floats?
        # At the very least, I think we can ensure that lists aren't passed.
        if isinstance(values, list):
            values = np.asarray(values)
        if is_float_dtype(values):
            raise TypeError("PeriodIndex._simple_new does not accept floats.")
        values = PeriodArray(values, freq=freq)

        if not isinstance(values, PeriodArray):
            raise TypeError("PeriodIndex._simple_new only accepts PeriodArray")
        result = object.__new__(cls)
        result._data = values
        result.name = name
        result._reset_identity()
        return result
Beispiel #10
0
def pad_1d(values, limit=None, mask=None, dtype=None):
    if dtype is None:
        dtype = values.dtype
    _method = None
    if is_float_dtype(values):
        name = 'pad_inplace_{name}'.format(name=dtype.name)
        _method = getattr(algos, name, None)
    elif is_datetime64_dtype(dtype) or is_datetime64tz_dtype(dtype):
        _method = _pad_1d_datetime
    elif is_integer_dtype(values):
        values = ensure_float64(values)
        _method = algos.pad_inplace_float64
    elif values.dtype == np.object_:
        _method = algos.pad_inplace_object
    elif is_timedelta64_dtype(values):
        # NaTs are treated identically to datetime64, so we can dispatch
        #  to that implementation
        _method = _pad_1d_datetime

    if _method is None:
        raise ValueError('Invalid dtype for pad_1d [{name}]'
                         .format(name=dtype.name))

    if mask is None:
        mask = isna(values)
    mask = mask.view(np.uint8)
    _method(values, mask, limit=limit)
    return values
Beispiel #11
0
    def __sub__(self, other):
        other = lib.item_from_zerodim(other)
        if isinstance(other, (ABCSeries, ABCDataFrame)):
            return NotImplemented

        # scalar others
        elif other is NaT:
            result = self._sub_nat()
        elif isinstance(other, (Tick, timedelta, np.timedelta64)):
            result = self._add_delta(-other)
        elif isinstance(other, DateOffset):
            # specifically _not_ a Tick
            result = self._add_offset(-other)
        elif isinstance(other, (datetime, np.datetime64)):
            result = self._sub_datetimelike_scalar(other)
        elif lib.is_integer(other):
            # This check must come after the check for np.timedelta64
            # as is_integer returns True for these
            maybe_integer_op_deprecated(self)
            result = self._time_shift(-other)

        elif isinstance(other, Period):
            result = self._sub_period(other)

        # array-like others
        elif is_timedelta64_dtype(other):
            # TimedeltaIndex, ndarray[timedelta64]
            result = self._add_delta(-other)
        elif is_offsetlike(other):
            # Array/Index of DateOffset objects
            result = self._addsub_offset_array(other, operator.sub)
        elif is_datetime64_dtype(other) or is_datetime64tz_dtype(other):
            # DatetimeIndex, ndarray[datetime64]
            result = self._sub_datetime_arraylike(other)
        elif is_period_dtype(other):
            # PeriodIndex
            result = self._sub_period_array(other)
        elif is_integer_dtype(other):
            maybe_integer_op_deprecated(self)
            result = self._addsub_int_array(other, operator.sub)
        elif isinstance(other, ABCIndexClass):
            raise TypeError("cannot subtract {cls} and {typ}"
                            .format(cls=type(self).__name__,
                                    typ=type(other).__name__))
        elif is_float_dtype(other):
            # Explicitly catch invalid dtypes
            raise TypeError("cannot subtract {dtype}-dtype from {cls}"
                            .format(dtype=other.dtype,
                                    cls=type(self).__name__))
        elif is_extension_array_dtype(other):
            # Categorical op will raise; defer explicitly
            return NotImplemented
        else:  # pragma: no cover
            return NotImplemented

        if is_timedelta64_dtype(result) and isinstance(result, np.ndarray):
            from pandas.core.arrays import TimedeltaArrayMixin
            # TODO: infer freq?
            return TimedeltaArrayMixin(result)
        return result
Beispiel #12
0
        def __sub__(self, other):
            from pandas import Index

            other = lib.item_from_zerodim(other)
            if isinstance(other, (ABCSeries, ABCDataFrame)):
                return NotImplemented

            # scalar others
            elif other is NaT:
                result = self._sub_nat()
            elif isinstance(other, (Tick, timedelta, np.timedelta64)):
                result = self._add_delta(-other)
            elif isinstance(other, DateOffset):
                # specifically _not_ a Tick
                result = self._add_offset(-other)
            elif isinstance(other, (datetime, np.datetime64)):
                result = self._sub_datelike(other)
            elif is_integer(other):
                # This check must come after the check for np.timedelta64
                # as is_integer returns True for these
                result = self.shift(-other)
            elif isinstance(other, Period):
                result = self._sub_period(other)

            # array-like others
            elif is_timedelta64_dtype(other):
                # TimedeltaIndex, ndarray[timedelta64]
                result = self._add_delta(-other)
            elif is_offsetlike(other):
                # Array/Index of DateOffset objects
                result = self._addsub_offset_array(other, operator.sub)
            elif is_datetime64_dtype(other) or is_datetime64tz_dtype(other):
                # DatetimeIndex, ndarray[datetime64]
                result = self._sub_datelike(other)
            elif isinstance(other, Index):
                raise TypeError("cannot subtract {cls} and {typ}"
                                .format(cls=type(self).__name__,
                                        typ=type(other).__name__))
            elif is_integer_dtype(other) and self.freq is None:
                # GH#19123
                raise NullFrequencyError("Cannot shift with no freq")

            elif is_float_dtype(other):
                # Explicitly catch invalid dtypes
                raise TypeError("cannot subtract {dtype}-dtype from {cls}"
                                .format(dtype=other.dtype,
                                        cls=type(self).__name__))
            else:  # pragma: no cover
                return NotImplemented

            if result is NotImplemented:
                return NotImplemented
            elif not isinstance(result, Index):
                # Index.__new__ will choose appropriate subclass for dtype
                result = Index(result)
            res_name = ops.get_op_result_name(self, other)
            result.name = res_name
            return result
Beispiel #13
0
def _get_values(values, skipna, fill_value=None, fill_value_typ=None,
                isfinite=False, copy=True, mask=None, compute_mask=True):
    """ utility to get the values view, mask, dtype
    if necessary copy and mask using the specified fill_value
    copy = True will force the copy
    """
    if skipna:
        compute_mask = True

    if is_datetime64tz_dtype(values):
        # com.values_from_object returns M8[ns] dtype instead of tz-aware,
        #  so this case must be handled separately from the rest
        dtype = values.dtype
        values = getattr(values, "_values", values)
    else:
        values = com.values_from_object(values)
        dtype = values.dtype

    if mask is None and compute_mask:
        if isfinite:
            mask = _isfinite(values)
        else:
            mask = isna(values)

    if is_datetime_or_timedelta_dtype(values) or is_datetime64tz_dtype(values):
        # changing timedelta64/datetime64 to int64 needs to happen after
        #  finding `mask` above
        values = getattr(values, "asi8", values)
        values = values.view(np.int64)

    dtype_ok = _na_ok_dtype(dtype)

    # get our fill value (in case we need to provide an alternative
    # dtype for it)
    fill_value = _get_fill_value(dtype, fill_value=fill_value,
                                 fill_value_typ=fill_value_typ)

    if skipna:
        if copy:
            values = values.copy()
        if dtype_ok:
            np.putmask(values, mask, fill_value)

        # promote if needed
        else:
            values, changed = maybe_upcast_putmask(values, mask, fill_value)

    elif copy:
        values = values.copy()

    # return a platform independent precision dtype
    dtype_max = dtype
    if is_integer_dtype(dtype) or is_bool_dtype(dtype):
        dtype_max = np.int64
    elif is_float_dtype(dtype):
        dtype_max = np.float64

    return values, mask, dtype, dtype_max, fill_value
Beispiel #14
0
    def __add__(self, other):
        other = lib.item_from_zerodim(other)
        if isinstance(other, (ABCSeries, ABCDataFrame)):
            return NotImplemented

        # scalar others
        elif other is NaT:
            result = self._add_nat()
        elif isinstance(other, (Tick, timedelta, np.timedelta64)):
            result = self._add_delta(other)
        elif isinstance(other, DateOffset):
            # specifically _not_ a Tick
            result = self._add_offset(other)
        elif isinstance(other, (datetime, np.datetime64)):
            result = self._add_datetimelike_scalar(other)
        elif lib.is_integer(other):
            # This check must come after the check for np.timedelta64
            # as is_integer returns True for these
            maybe_integer_op_deprecated(self)
            result = self._time_shift(other)

        # array-like others
        elif is_timedelta64_dtype(other):
            # TimedeltaIndex, ndarray[timedelta64]
            result = self._add_delta(other)
        elif is_offsetlike(other):
            # Array/Index of DateOffset objects
            result = self._addsub_offset_array(other, operator.add)
        elif is_datetime64_dtype(other) or is_datetime64tz_dtype(other):
            # DatetimeIndex, ndarray[datetime64]
            return self._add_datetime_arraylike(other)
        elif is_integer_dtype(other):
            maybe_integer_op_deprecated(self)
            result = self._addsub_int_array(other, operator.add)
        elif is_float_dtype(other):
            # Explicitly catch invalid dtypes
            raise TypeError("cannot add {dtype}-dtype to {cls}"
                            .format(dtype=other.dtype,
                                    cls=type(self).__name__))
        elif is_period_dtype(other):
            # if self is a TimedeltaArray and other is a PeriodArray with
            #  a timedelta-like (i.e. Tick) freq, this operation is valid.
            #  Defer to the PeriodArray implementation.
            # In remaining cases, this will end up raising TypeError.
            return NotImplemented
        elif is_extension_array_dtype(other):
            # Categorical op will raise; defer explicitly
            return NotImplemented
        else:  # pragma: no cover
            return NotImplemented

        if is_timedelta64_dtype(result) and isinstance(result, np.ndarray):
            from pandas.core.arrays import TimedeltaArrayMixin
            # TODO: infer freq?
            return TimedeltaArrayMixin(result)
        return result
Beispiel #15
0
def nansem(values, axis=None, skipna=True, ddof=1):
    var = nanvar(values, axis, skipna, ddof=ddof)

    mask = isna(values)
    if not is_float_dtype(values.dtype):
        values = values.astype('f8')
    count, _ = _get_counts_nanvar(mask, axis, ddof, values.dtype)
    var = nanvar(values, axis, skipna, ddof=ddof)

    return np.sqrt(var) / np.sqrt(count)
Beispiel #16
0
def nansum(values, axis=None, skipna=True, min_count=0):
    values, mask, dtype, dtype_max = _get_values(values, skipna, 0)
    dtype_sum = dtype_max
    if is_float_dtype(dtype):
        dtype_sum = dtype
    elif is_timedelta64_dtype(dtype):
        dtype_sum = np.float64
    the_sum = values.sum(axis, dtype=dtype_sum)
    the_sum = _maybe_null_out(the_sum, axis, mask, min_count=min_count)

    return _wrap_results(the_sum, dtype)
Beispiel #17
0
        def integer_arithmetic_method(self, other):

            op_name = op.__name__
            mask = None

            if isinstance(other, (ABCSeries, ABCIndexClass)):
                # Rely on pandas to unbox and dispatch to us.
                return NotImplemented

            if getattr(other, 'ndim', 0) > 1:
                raise NotImplementedError(
                    "can only perform ops with 1-d structures")

            if isinstance(other, IntegerArray):
                other, mask = other._data, other._mask

            elif getattr(other, 'ndim', None) == 0:
                other = other.item()

            elif is_list_like(other):
                other = np.asarray(other)
                if not other.ndim:
                    other = other.item()
                elif other.ndim == 1:
                    if not (is_float_dtype(other) or is_integer_dtype(other)):
                        raise TypeError(
                            "can only perform ops with numeric values")
            else:
                if not (is_float(other) or is_integer(other)):
                    raise TypeError("can only perform ops with numeric values")

            # nans propagate
            if mask is None:
                mask = self._mask
            else:
                mask = self._mask | mask

            # 1 ** np.nan is 1. So we have to unmask those.
            if op_name == 'pow':
                mask = np.where(self == 1, False, mask)

            elif op_name == 'rpow':
                mask = np.where(other == 1, False, mask)

            with np.errstate(all='ignore'):
                result = op(self._data, other)

            # divmod returns a tuple
            if op_name == 'divmod':
                div, mod = result
                return (self._maybe_mask_result(div, mask, other, 'floordiv'),
                        self._maybe_mask_result(mod, mask, other, 'mod'))

            return self._maybe_mask_result(result, mask, other, op_name)
Beispiel #18
0
    def _simple_new(cls, values, name=None, freq=None, **kwargs):
        """
        Values can be any type that can be coerced to Periods.
        Ordinals in an ndarray are fastpath-ed to `_from_ordinals`
        """
        if not is_integer_dtype(values):
            values = np.array(values, copy=False)
            if len(values) > 0 and is_float_dtype(values):
                raise TypeError("PeriodIndex can't take floats")
            return cls(values, name=name, freq=freq, **kwargs)

        return cls._from_ordinals(values, name, freq, **kwargs)
Beispiel #19
0
def fill_zeros(result, x, y, name, fill):
    """
    if this is a reversed op, then flip x,y

    if we have an integer value (or array in y)
    and we have 0's, fill them with the fill,
    return the result

    mask the nan's from x
    """
    if fill is None or is_float_dtype(result):
        return result

    if name.startswith(('r', '__r')):
        x, y = y, x

    is_variable_type = (hasattr(y, 'dtype') or hasattr(y, 'type'))
    is_scalar_type = is_scalar(y)

    if not is_variable_type and not is_scalar_type:
        return result

    if is_scalar_type:
        y = np.array(y)

    if is_integer_dtype(y):

        if (y == 0).any():

            # GH 7325, mask and nans must be broadcastable (also: PR 9308)
            # Raveling and then reshaping makes np.putmask faster
            mask = ((y == 0) & ~np.isnan(result)).ravel()

            shape = result.shape
            result = result.astype('float64', copy=False).ravel()

            np.putmask(result, mask, fill)

            # if we have a fill of inf, then sign it correctly
            # (GH 6178 and PR 9308)
            if np.isinf(fill):
                signs = y if name.startswith(('r', '__r')) else x
                signs = np.sign(signs.astype('float', copy=False))
                negative_inf_mask = (signs.ravel() < 0) & mask
                np.putmask(result, negative_inf_mask, -fill)

            if "floordiv" in name:  # (PR 9308)
                nan_mask = ((y == 0) & (x == 0)).ravel()
                np.putmask(result, nan_mask, np.nan)

            result = result.reshape(shape)

    return result
Beispiel #20
0
def _get_next_label(label):
    dtype = getattr(label, 'dtype', type(label))
    if isinstance(label, (Timestamp, Timedelta)):
        dtype = 'datetime64'
    if is_datetime_or_timedelta_dtype(dtype) or is_datetime64tz_dtype(dtype):
        return label + np.timedelta64(1, 'ns')
    elif is_integer_dtype(dtype):
        return label + 1
    elif is_float_dtype(dtype):
        return np.nextafter(label, np.infty)
    else:
        raise TypeError('cannot determine next label for type {typ!r}'
                        .format(typ=type(label)))
Beispiel #21
0
def _get_prev_label(label):
    dtype = getattr(label, 'dtype', type(label))
    if isinstance(label, (Timestamp, Timedelta)):
        dtype = 'datetime64'
    if is_datetime_or_timedelta_dtype(dtype):
        return label - np.timedelta64(1, 'ns')
    elif is_integer_dtype(dtype):
        return label - 1
    elif is_float_dtype(dtype):
        return np.nextafter(label, -np.infty)
    else:
        raise TypeError('cannot determine next label for type %r'
                        % type(label))
Beispiel #22
0
    def _simple_new(cls, values, freq=None):
        """
        Values can be any type that can be coerced to Periods.
        Ordinals in an ndarray are fastpath-ed to `_from_ordinals`
        """
        if not is_integer_dtype(values):
            values = np.array(values, copy=False)
            if len(values) > 0 and is_float_dtype(values):
                raise TypeError("{cls} can't take floats"
                                .format(cls=cls.__name__))
            return cls(values, freq=freq)

        return cls._from_ordinals(values, freq)
Beispiel #23
0
        def __add__(self, other):
            other = lib.item_from_zerodim(other)
            if isinstance(other, (ABCSeries, ABCDataFrame)):
                return NotImplemented

            # scalar others
            elif other is NaT:
                result = self._add_nat()
            elif isinstance(other, (Tick, timedelta, np.timedelta64)):
                result = self._add_delta(other)
            elif isinstance(other, DateOffset):
                # specifically _not_ a Tick
                result = self._add_offset(other)
            elif isinstance(other, (datetime, np.datetime64)):
                result = self._add_datelike(other)
            elif is_integer(other):
                # This check must come after the check for np.timedelta64
                # as is_integer returns True for these
                result = self.shift(other)

            # array-like others
            elif is_timedelta64_dtype(other):
                # TimedeltaIndex, ndarray[timedelta64]
                result = self._add_delta(other)
            elif is_offsetlike(other):
                # Array/Index of DateOffset objects
                result = self._addsub_offset_array(other, operator.add)
            elif is_datetime64_dtype(other) or is_datetime64tz_dtype(other):
                # DatetimeIndex, ndarray[datetime64]
                return self._add_datelike(other)
            elif is_integer_dtype(other):
                result = self._addsub_int_array(other, operator.add)
            elif is_float_dtype(other) or is_period_dtype(other):
                # Explicitly catch invalid dtypes
                raise TypeError("cannot add {dtype}-dtype to {cls}"
                                .format(dtype=other.dtype,
                                        cls=type(self).__name__))
            elif is_categorical_dtype(other):
                # Categorical op will raise; defer explicitly
                return NotImplemented
            else:  # pragma: no cover
                return NotImplemented

            if result is NotImplemented:
                return NotImplemented
            elif not isinstance(result, Index):
                # Index.__new__ will choose appropriate subclass for dtype
                result = Index(result)
            res_name = ops.get_op_result_name(self, other)
            result.name = res_name
            return result
Beispiel #24
0
def test_is_float_dtype():
    assert not com.is_float_dtype(str)
    assert not com.is_float_dtype(int)
    assert not com.is_float_dtype(pd.Series([1, 2]))
    assert not com.is_float_dtype(np.array(['a', 'b']))

    assert com.is_float_dtype(float)
    assert com.is_float_dtype(pd.Index([1, 2.]))
Beispiel #25
0
    def test_setitem_dtype_upcast(self):

        # GH3216
        df = DataFrame([{"a": 1}, {"a": 3, "b": 2}])
        df['c'] = np.nan
        assert df['c'].dtype == np.float64

        df.loc[0, 'c'] = 'foo'
        expected = DataFrame([{"a": 1, "c": 'foo'},
                              {"a": 3, "b": 2, "c": np.nan}])
        tm.assert_frame_equal(df, expected)

        # GH10280
        df = DataFrame(np.arange(6, dtype='int64').reshape(2, 3),
                       index=list('ab'),
                       columns=['foo', 'bar', 'baz'])

        for val in [3.14, 'wxyz']:
            left = df.copy()
            left.loc['a', 'bar'] = val
            right = DataFrame([[0, val, 2], [3, 4, 5]], index=list('ab'),
                              columns=['foo', 'bar', 'baz'])

            tm.assert_frame_equal(left, right)
            assert is_integer_dtype(left['foo'])
            assert is_integer_dtype(left['baz'])

        left = DataFrame(np.arange(6, dtype='int64').reshape(2, 3) / 10.0,
                         index=list('ab'),
                         columns=['foo', 'bar', 'baz'])
        left.loc['a', 'bar'] = 'wxyz'

        right = DataFrame([[0, 'wxyz', .2], [.3, .4, .5]], index=list('ab'),
                          columns=['foo', 'bar', 'baz'])

        tm.assert_frame_equal(left, right)
        assert is_float_dtype(left['foo'])
        assert is_float_dtype(left['baz'])
Beispiel #26
0
def test_from_to_scipy(spmatrix, index, columns, fill_value, dtype):
    # GH 4343
    tm.skip_if_no_package('scipy')

    # Make one ndarray and from it one sparse matrix, both to be used for
    # constructing frames and comparing results
    arr = np.eye(3, dtype=dtype)
    # GH 16179
    arr[0, 1] = dtype(2)
    try:
        spm = spmatrix(arr)
        assert spm.dtype == arr.dtype
    except (TypeError, AssertionError):
        # If conversion to sparse fails for this spmatrix type and arr.dtype,
        # then the combination is not currently supported in NumPy, so we
        # can just skip testing it thoroughly
        return

    sdf = pd.SparseDataFrame(spm, index=index, columns=columns,
                             default_fill_value=fill_value)

    # Expected result construction is kind of tricky for all
    # dtype-fill_value combinations; easiest to cast to something generic
    # and except later on
    rarr = arr.astype(object)
    rarr[arr == 0] = np.nan
    expected = pd.SparseDataFrame(rarr, index=index, columns=columns).fillna(
        fill_value if fill_value is not None else np.nan)

    # Assert frame is as expected
    sdf_obj = sdf.astype(object)
    tm.assert_sp_frame_equal(sdf_obj, expected)
    tm.assert_frame_equal(sdf_obj.to_dense(), expected.to_dense())

    # Assert spmatrices equal
    assert dict(sdf.to_coo().todok()) == dict(spm.todok())

    # Ensure dtype is preserved if possible
    was_upcast = ((fill_value is None or is_float(fill_value)) and
                  not is_object_dtype(dtype) and
                  not is_float_dtype(dtype))
    res_dtype = (bool if is_bool_dtype(dtype) else
                 float if was_upcast else
                 dtype)
    tm.assert_contains_all(sdf.dtypes, {np.dtype(res_dtype)})
    assert sdf.to_coo().dtype == res_dtype

    # However, adding a str column results in an upcast to object
    sdf['strings'] = np.arange(len(sdf)).astype(str)
    assert sdf.to_coo().dtype == np.object_
Beispiel #27
0
    def test_set_value(self):

        with catch_warnings(record=True):

            for label in self.panel4d.labels:
                for item in self.panel4d.items:
                    for mjr in self.panel4d.major_axis[::2]:
                        for mnr in self.panel4d.minor_axis:
                            self.panel4d.set_value(label, item, mjr, mnr, 1.)
                            tm.assert_almost_equal(
                                self.panel4d[label][item][mnr][mjr], 1.)

            res3 = self.panel4d.set_value('l4', 'ItemE', 'foobar', 'baz', 5)
            assert is_float_dtype(res3['l4'].values)

            # resize
            res = self.panel4d.set_value('l4', 'ItemE', 'foo', 'bar', 1.5)
            assert isinstance(res, Panel4D)
            assert res is not self.panel4d
            assert res.get_value('l4', 'ItemE', 'foo', 'bar') == 1.5

            res3 = self.panel4d.set_value('l4', 'ItemE', 'foobar', 'baz', 5)
            assert is_float_dtype(res3['l4'].values)
Beispiel #28
0
def nanvar(values, axis=None, skipna=True, ddof=1):

    values = _values_from_object(values)
    dtype = values.dtype
    mask = isna(values)
    if is_any_int_dtype(values):
        values = values.astype('f8')
        values[mask] = np.nan

    if is_float_dtype(values):
        count, d = _get_counts_nanvar(mask, axis, ddof, values.dtype)
    else:
        count, d = _get_counts_nanvar(mask, axis, ddof)

    if skipna:
        values = values.copy()
        np.putmask(values, mask, 0)

    # xref GH10242
    # Compute variance via two-pass algorithm, which is stable against
    # cancellation errors and relatively accurate for small numbers of
    # observations.
    #
    # See https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
    avg = _ensure_numeric(values.sum(axis=axis, dtype=np.float64)) / count
    if axis is not None:
        avg = np.expand_dims(avg, axis)
    sqr = _ensure_numeric((avg - values)**2)
    np.putmask(sqr, mask, 0)
    result = sqr.sum(axis=axis, dtype=np.float64) / d

    # Return variance as np.float64 (the datatype used in the accumulator),
    # unless we were dealing with a float array, in which case use the same
    # precision as the original values array.
    if is_float_dtype(dtype):
        result = result.astype(dtype)
    return _wrap_results(result, values.dtype)
Beispiel #29
0
def nanmean(values, axis=None, skipna=True, mask=None):
    """
    Compute the mean of the element along an axis ignoring NaNs

    Parameters
    ----------
    values : ndarray
    axis: int, optional
    skipna : bool, default True
    mask : ndarray[bool], optional
        nan-mask if known

    Returns
    -------
    result : float
        Unless input is a float array, in which case use the same
        precision as the input array.

    Examples
    --------
    >>> import pandas.core.nanops as nanops
    >>> s = pd.Series([1, 2, np.nan])
    >>> nanops.nanmean(s)
    1.5
    """
    values, mask, dtype, dtype_max, _ = _get_values(
        values, skipna, 0, mask=mask)
    dtype_sum = dtype_max
    dtype_count = np.float64
    if (is_integer_dtype(dtype) or is_timedelta64_dtype(dtype) or
            is_datetime64_dtype(dtype) or is_datetime64tz_dtype(dtype)):
        dtype_sum = np.float64
    elif is_float_dtype(dtype):
        dtype_sum = dtype
        dtype_count = dtype
    count = _get_counts(mask, axis, dtype=dtype_count)
    the_sum = _ensure_numeric(values.sum(axis, dtype=dtype_sum))

    if axis is not None and getattr(the_sum, 'ndim', False):
        with np.errstate(all="ignore"):
            # suppress division by zero warnings
            the_mean = the_sum / count
        ct_mask = count == 0
        if ct_mask.any():
            the_mean[ct_mask] = np.nan
    else:
        the_mean = the_sum / count if count > 0 else np.nan

    return _wrap_results(the_mean, dtype)
Beispiel #30
0
 def astype(self, dtype, copy=True):
     if is_object_dtype(dtype):
         return self._box_values_as_index()
     elif is_string_dtype(dtype) and not is_categorical_dtype(dtype):
         return Index(self.format(), name=self.name, dtype=object)
     elif is_integer_dtype(dtype):
         return Index(self.values.astype('i8', copy=copy), name=self.name,
                      dtype='i8')
     elif (is_datetime_or_timedelta_dtype(dtype) and
           not is_dtype_equal(self.dtype, dtype)) or is_float_dtype(dtype):
         # disallow conversion between datetime/timedelta,
         # and conversions for any datetimelike to float
         msg = 'Cannot cast {name} to dtype {dtype}'
         raise TypeError(msg.format(name=type(self).__name__, dtype=dtype))
     return super(DatetimeIndexOpsMixin, self).astype(dtype, copy=copy)
Beispiel #31
0
def array_equivalent(
    left, right, strict_nan: bool = False, dtype_equal: bool = False
) -> bool:
    """
    True if two arrays, left and right, have equal non-NaN elements, and NaNs
    in corresponding locations.  False otherwise. It is assumed that left and
    right are NumPy arrays of the same dtype. The behavior of this function
    (particularly with respect to NaNs) is not defined if the dtypes are
    different.

    Parameters
    ----------
    left, right : ndarrays
    strict_nan : bool, default False
        If True, consider NaN and None to be different.
    dtype_equal : bool, default False
        Whether `left` and `right` are known to have the same dtype
        according to `is_dtype_equal`. Some methods like `BlockManager.equals`.
        require that the dtypes match. Setting this to ``True`` can improve
        performance, but will give different results for arrays that are
        equal but different dtypes.

    Returns
    -------
    b : bool
        Returns True if the arrays are equivalent.

    Examples
    --------
    >>> array_equivalent(
    ...     np.array([1, 2, np.nan]),
    ...     np.array([1, 2, np.nan]))
    True
    >>> array_equivalent(
    ...     np.array([1, np.nan, 2]),
    ...     np.array([1, 2, np.nan]))
    False
    """
    left, right = np.asarray(left), np.asarray(right)

    # shape compat
    if left.shape != right.shape:
        return False

    if dtype_equal:
        # fastpath when we require that the dtypes match (Block.equals)
        if is_float_dtype(left.dtype) or is_complex_dtype(left.dtype):
            return _array_equivalent_float(left, right)
        elif is_datetimelike_v_numeric(left.dtype, right.dtype):
            return False
        elif needs_i8_conversion(left.dtype):
            return _array_equivalent_datetimelike(left, right)
        elif is_string_dtype(left.dtype):
            # TODO: fastpath for pandas' StringDtype
            return _array_equivalent_object(left, right, strict_nan)
        else:
            return np.array_equal(left, right)

    # Slow path when we allow comparing different dtypes.
    # Object arrays can contain None, NaN and NaT.
    # string dtypes must be come to this path for NumPy 1.7.1 compat
    if is_string_dtype(left.dtype) or is_string_dtype(right.dtype):
        return _array_equivalent_object(left, right, strict_nan)

    # NaNs can occur in float and complex arrays.
    if is_float_dtype(left.dtype) or is_complex_dtype(left.dtype):
        if not (left.size and right.size):
            return True
        return ((left == right) | (isna(left) & isna(right))).all()

    elif is_datetimelike_v_numeric(left, right):
        # GH#29553 avoid numpy deprecation warning
        return False

    elif needs_i8_conversion(left.dtype) or needs_i8_conversion(right.dtype):
        # datetime64, timedelta64, Period
        if not is_dtype_equal(left.dtype, right.dtype):
            return False

        left = left.view("i8")
        right = right.view("i8")

    # if we have structured dtypes, compare first
    if (
        left.dtype.type is np.void or right.dtype.type is np.void
    ) and left.dtype != right.dtype:
        return False

    return np.array_equal(left, right)
Beispiel #32
0
def sanitize_array(data,
                   index,
                   dtype=None,
                   copy=False,
                   raise_cast_failure=False):
    """
    Sanitize input data to an ndarray, copy if specified, coerce to the
    dtype if specified.
    """
    if dtype is not None:
        dtype = pandas_dtype(dtype)

    if isinstance(data, ma.MaskedArray):
        mask = ma.getmaskarray(data)
        if mask.any():
            data, fill_value = maybe_upcast(data, copy=True)
            data.soften_mask()  # set hardmask False if it was True
            data[mask] = fill_value
        else:
            data = data.copy()

    data = extract_array(data, extract_numpy=True)

    # GH#846
    if isinstance(data, np.ndarray):

        if dtype is not None:
            subarr = np.array(data, copy=False)

            # possibility of nan -> garbage
            if is_float_dtype(data.dtype) and is_integer_dtype(dtype):
                try:
                    subarr = _try_cast(data, True, dtype, copy, True)
                except ValueError:
                    if copy:
                        subarr = data.copy()
            else:
                subarr = _try_cast(data, True, dtype, copy, raise_cast_failure)
        elif isinstance(data, Index):
            # don't coerce Index types
            # e.g. indexes can have different conversions (so don't fast path
            # them)
            # GH#6140
            subarr = sanitize_index(data, index, copy=copy)
        else:

            # we will try to copy be-definition here
            subarr = _try_cast(data, True, dtype, copy, raise_cast_failure)

    elif isinstance(data, ExtensionArray):
        if isinstance(data, ABCPandasArray):
            # We don't want to let people put our PandasArray wrapper
            # (the output of Series/Index.array), into a Series. So
            # we explicitly unwrap it here.
            subarr = data.to_numpy()
        else:
            subarr = data

        # everything else in this block must also handle ndarray's,
        # becuase we've unwrapped PandasArray into an ndarray.

        if dtype is not None:
            subarr = data.astype(dtype)

        if copy:
            subarr = data.copy()
        return subarr

    elif isinstance(data, (list, tuple)) and len(data) > 0:
        if dtype is not None:
            try:
                subarr = _try_cast(data, False, dtype, copy,
                                   raise_cast_failure)
            except Exception:
                if raise_cast_failure:  # pragma: no cover
                    raise
                subarr = np.array(data, dtype=object, copy=copy)
                subarr = lib.maybe_convert_objects(subarr)

        else:
            subarr = maybe_convert_platform(data)

        subarr = maybe_cast_to_datetime(subarr, dtype)

    elif isinstance(data, range):
        # GH#16804
        arr = np.arange(data.start, data.stop, data.step, dtype='int64')
        subarr = _try_cast(arr, False, dtype, copy, raise_cast_failure)
    else:
        subarr = _try_cast(data, False, dtype, copy, raise_cast_failure)

    # scalar like, GH
    if getattr(subarr, 'ndim', 0) == 0:
        if isinstance(data, list):  # pragma: no cover
            subarr = np.array(data, dtype=object)
        elif index is not None:
            value = data

            # figure out the dtype from the value (upcast if necessary)
            if dtype is None:
                dtype, value = infer_dtype_from_scalar(value)
            else:
                # need to possibly convert the value here
                value = maybe_cast_to_datetime(value, dtype)

            subarr = construct_1d_arraylike_from_scalar(
                value, len(index), dtype)

        else:
            return subarr.item()

    # the result that we want
    elif subarr.ndim == 1:
        if index is not None:

            # a 1-element ndarray
            if len(subarr) != len(index) and len(subarr) == 1:
                subarr = construct_1d_arraylike_from_scalar(
                    subarr[0], len(index), subarr.dtype)

    elif subarr.ndim > 1:
        if isinstance(data, np.ndarray):
            raise Exception('Data must be 1-dimensional')
        else:
            subarr = com.asarray_tuplesafe(data, dtype=dtype)

    # This is to prevent mixed-type Series getting all casted to
    # NumPy string type, e.g. NaN --> '-1#IND'.
    if issubclass(subarr.dtype.type, str):
        # GH#16605
        # If not empty convert the data to dtype
        # GH#19853: If data is a scalar, subarr has already the result
        if not lib.is_scalar(data):
            if not np.all(isna(data)):
                data = np.array(data, dtype=dtype, copy=False)
            subarr = np.array(data, dtype=object, copy=copy)

    if is_object_dtype(subarr.dtype) and dtype != 'object':
        inferred = lib.infer_dtype(subarr, skipna=False)
        if inferred == 'period':
            try:
                subarr = period_array(subarr)
            except IncompatibleFrequency:
                pass

    return subarr
Beispiel #33
0
def get_empty_dtype_and_na(join_units):
    """
    Return dtype and N/A values to use when concatenating specified units.

    Returned N/A value may be None which means there was no casting involved.

    Returns
    -------
    dtype
    na
    """

    if len(join_units) == 1:
        blk = join_units[0].block
        if blk is None:
            return np.float64, np.nan

    if is_uniform_reindex(join_units):
        # XXX: integrate property
        empty_dtype = join_units[0].block.dtype
        upcasted_na = join_units[0].block.fill_value
        return empty_dtype, upcasted_na

    has_none_blocks = False
    dtypes = [None] * len(join_units)
    for i, unit in enumerate(join_units):
        if unit.block is None:
            has_none_blocks = True
        else:
            dtypes[i] = unit.dtype

    upcast_classes = defaultdict(list)
    null_upcast_classes = defaultdict(list)
    for dtype, unit in zip(dtypes, join_units):
        if dtype is None:
            continue

        if is_categorical_dtype(dtype):
            upcast_cls = 'category'
        elif is_datetimetz(dtype):
            upcast_cls = 'datetimetz'
        elif issubclass(dtype.type, np.bool_):
            upcast_cls = 'bool'
        elif issubclass(dtype.type, np.object_):
            upcast_cls = 'object'
        elif is_datetime64_dtype(dtype):
            upcast_cls = 'datetime'
        elif is_timedelta64_dtype(dtype):
            upcast_cls = 'timedelta'
        elif is_float_dtype(dtype) or is_numeric_dtype(dtype):
            upcast_cls = dtype.name
        else:
            upcast_cls = 'float'

        # Null blocks should not influence upcast class selection, unless there
        # are only null blocks, when same upcasting rules must be applied to
        # null upcast classes.
        if unit.is_na:
            null_upcast_classes[upcast_cls].append(dtype)
        else:
            upcast_classes[upcast_cls].append(dtype)

    if not upcast_classes:
        upcast_classes = null_upcast_classes

    # create the result
    if 'object' in upcast_classes:
        return np.dtype(np.object_), np.nan
    elif 'bool' in upcast_classes:
        if has_none_blocks:
            return np.dtype(np.object_), np.nan
        else:
            return np.dtype(np.bool_), None
    elif 'category' in upcast_classes:
        return np.dtype(np.object_), np.nan
    elif 'datetimetz' in upcast_classes:
        dtype = upcast_classes['datetimetz']
        return dtype[0], tslibs.iNaT
    elif 'datetime' in upcast_classes:
        return np.dtype('M8[ns]'), tslibs.iNaT
    elif 'timedelta' in upcast_classes:
        return np.dtype('m8[ns]'), tslibs.iNaT
    else:  # pragma
        g = np.find_common_type(upcast_classes, [])
        if is_float_dtype(g):
            return g, g.type(np.nan)
        elif is_numeric_dtype(g):
            if has_none_blocks:
                return np.float64, np.nan
            else:
                return g, None

    msg = "invalid dtype determination in get_concat_dtype"
    raise AssertionError(msg)
Beispiel #34
0
def sequence_to_td64ns(data, copy=False, unit="ns", errors="raise"):
    """
    Parameters
    ----------
    array : list-like
    copy : bool, default False
    unit : str, default "ns"
        The timedelta unit to treat integers as multiples of.
    errors : {"raise", "coerce", "ignore"}, default "raise"
        How to handle elements that cannot be converted to timedelta64[ns].
        See ``pandas.to_timedelta`` for details.

    Returns
    -------
    converted : numpy.ndarray
        The sequence converted to a numpy array with dtype ``timedelta64[ns]``.
    inferred_freq : Tick or None
        The inferred frequency of the sequence.

    Raises
    ------
    ValueError : Data cannot be converted to timedelta64[ns].

    Notes
    -----
    Unlike `pandas.to_timedelta`, if setting ``errors=ignore`` will not cause
    errors to be ignored; they are caught and subsequently ignored at a
    higher level.
    """
    inferred_freq = None
    unit = parse_timedelta_unit(unit)

    # Unwrap whatever we have into a np.ndarray
    if not hasattr(data, 'dtype'):
        # e.g. list, tuple
        if np.ndim(data) == 0:
            # i.e. generator
            data = list(data)
        data = np.array(data, copy=False)
    elif isinstance(data, ABCSeries):
        data = data._values
    elif isinstance(data, (ABCTimedeltaIndex, TimedeltaArrayMixin)):
        inferred_freq = data.freq
        data = data._data

    # Convert whatever we have into timedelta64[ns] dtype
    if is_object_dtype(data) or is_string_dtype(data):
        # no need to make a copy, need to convert if string-dtyped
        data = objects_to_td64ns(data, unit=unit, errors=errors)
        copy = False

    elif is_integer_dtype(data):
        # treat as multiples of the given unit
        data, copy_made = ints_to_td64ns(data, unit=unit)
        copy = copy and not copy_made

    elif is_float_dtype(data):
        # treat as multiples of the given unit.  If after converting to nanos,
        #  there are fractional components left, these are truncated
        #  (i.e. NOT rounded)
        mask = np.isnan(data)
        coeff = np.timedelta64(1, unit) / np.timedelta64(1, 'ns')
        data = (coeff * data).astype(np.int64).view('timedelta64[ns]')
        data[mask] = iNaT
        copy = False

    elif is_timedelta64_dtype(data):
        if data.dtype != _TD_DTYPE:
            # non-nano unit
            # TODO: watch out for overflows
            data = data.astype(_TD_DTYPE)
            copy = False

    elif is_datetime64_dtype(data):
        # GH#23539
        warnings.warn("Passing datetime64-dtype data to TimedeltaIndex is "
                      "deprecated, will raise a TypeError in a future "
                      "version",
                      FutureWarning, stacklevel=4)
        data = ensure_int64(data).view(_TD_DTYPE)

    else:
        raise TypeError("dtype {dtype} cannot be converted to timedelta64[ns]"
                        .format(dtype=data.dtype))

    data = np.array(data, copy=copy)
    assert data.dtype == 'm8[ns]', data
    return data, inferred_freq
Beispiel #35
0
def nanvar(values, axis=None, skipna=True, ddof=1, mask=None):
    """
    Compute the variance along given axis while ignoring NaNs

    Parameters
    ----------
    values : ndarray
    axis: int, optional
    skipna : bool, default True
    ddof : int, default 1
        Delta Degrees of Freedom. The divisor used in calculations is N - ddof,
        where N represents the number of elements.
    mask : ndarray[bool], optional
        nan-mask if known

    Returns
    -------
    result : float
        Unless input is a float array, in which case use the same
        precision as the input array.

    Examples
    --------
    >>> import pandas.core.nanops as nanops
    >>> s = pd.Series([1, np.nan, 2, 3])
    >>> nanops.nanvar(s)
    1.0
    """
    values = extract_array(values, extract_numpy=True)
    dtype = values.dtype
    mask = _maybe_get_mask(values, skipna, mask)
    if is_any_int_dtype(values):
        values = values.astype("f8")
        if mask is not None:
            values[mask] = np.nan

    if is_float_dtype(values):
        count, d = _get_counts_nanvar(values.shape, mask, axis, ddof,
                                      values.dtype)
    else:
        count, d = _get_counts_nanvar(values.shape, mask, axis, ddof)

    if skipna and mask is not None:
        values = values.copy()
        np.putmask(values, mask, 0)

    # xref GH10242
    # Compute variance via two-pass algorithm, which is stable against
    # cancellation errors and relatively accurate for small numbers of
    # observations.
    #
    # See https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
    avg = _ensure_numeric(values.sum(axis=axis, dtype=np.float64)) / count
    if axis is not None:
        avg = np.expand_dims(avg, axis)
    sqr = _ensure_numeric((avg - values)**2)
    if mask is not None:
        np.putmask(sqr, mask, 0)
    result = sqr.sum(axis=axis, dtype=np.float64) / d

    # Return variance as np.float64 (the datatype used in the accumulator),
    # unless we were dealing with a float array, in which case use the same
    # precision as the original values array.
    if is_float_dtype(dtype):
        result = result.astype(dtype)
    return _wrap_results(result, values.dtype)
Beispiel #36
0
def _get_empty_dtype_and_na(
        join_units: Sequence[JoinUnit]) -> Tuple[DtypeObj, Any]:
    """
    Return dtype and N/A values to use when concatenating specified units.

    Returned N/A value may be None which means there was no casting involved.

    Returns
    -------
    dtype
    na
    """
    if len(join_units) == 1:
        blk = join_units[0].block
        if blk is None:
            return np.dtype(np.float64), np.nan

    if _is_uniform_reindex(join_units):
        # FIXME: integrate property
        empty_dtype = join_units[0].block.dtype
        upcasted_na = join_units[0].block.fill_value
        return empty_dtype, upcasted_na

    has_none_blocks = False
    dtypes = [None] * len(join_units)
    for i, unit in enumerate(join_units):
        if unit.block is None:
            has_none_blocks = True
        else:
            dtypes[i] = unit.dtype

    upcast_classes = _get_upcast_classes(join_units, dtypes)

    # TODO: de-duplicate with maybe_promote?
    # create the result
    if "extension" in upcast_classes:
        if len(upcast_classes) == 1:
            cls = upcast_classes["extension"][0]
            return cls, cls.na_value
        else:
            return np.dtype("object"), np.nan
    elif "object" in upcast_classes:
        return np.dtype(np.object_), np.nan
    elif "bool" in upcast_classes:
        if has_none_blocks:
            return np.dtype(np.object_), np.nan
        else:
            return np.dtype(np.bool_), None
    elif "category" in upcast_classes:
        return np.dtype(np.object_), np.nan
    elif "datetimetz" in upcast_classes:
        # GH-25014. We use NaT instead of iNaT, since this eventually
        # ends up in DatetimeArray.take, which does not allow iNaT.
        dtype = upcast_classes["datetimetz"]
        return dtype[0], NaT
    elif "datetime" in upcast_classes:
        return np.dtype("M8[ns]"), np.datetime64("NaT", "ns")
    elif "timedelta" in upcast_classes:
        return np.dtype("m8[ns]"), np.timedelta64("NaT", "ns")
    else:
        try:
            common_dtype = np.find_common_type(upcast_classes, [])
        except TypeError:
            # At least one is an ExtensionArray
            return np.dtype(np.object_), np.nan
        else:
            if is_float_dtype(common_dtype):
                return common_dtype, common_dtype.type(np.nan)
            elif is_numeric_dtype(common_dtype):
                if has_none_blocks:
                    return np.dtype(np.float64), np.nan
                else:
                    return common_dtype, None

    msg = "invalid dtype determination in get_concat_dtype"
    raise AssertionError(msg)
Beispiel #37
0
 def _can_hold_na(self) -> bool:  # type: ignore[override]
     if is_float_dtype(self.dtype):
         return True
     else:
         return False
Beispiel #38
0
def nankurt(
    values: np.ndarray,
    axis: Optional[int] = None,
    skipna: bool = True,
    mask: Optional[np.ndarray] = None,
) -> float:
    """
    Compute the sample excess kurtosis

    The statistic computed here is the adjusted Fisher-Pearson standardized
    moment coefficient G2, computed directly from the second and fourth
    central moment.

    Parameters
    ----------
    values : ndarray
    axis: int, optional
    skipna : bool, default True
    mask : ndarray[bool], optional
        nan-mask if known

    Returns
    -------
    result : float64
        Unless input is a float array, in which case use the same
        precision as the input array.

    Examples
    --------
    >>> import pandas.core.nanops as nanops
    >>> s = pd.Series([1, np.nan, 1, 3, 2])
    >>> nanops.nankurt(s)
    -1.2892561983471076
    """
    values = extract_array(values, extract_numpy=True)
    mask = _maybe_get_mask(values, skipna, mask)
    if not is_float_dtype(values.dtype):
        values = values.astype("f8")
        count = _get_counts(values.shape, mask, axis)
    else:
        count = _get_counts(values.shape, mask, axis, dtype=values.dtype)

    if skipna and mask is not None:
        values = values.copy()
        np.putmask(values, mask, 0)

    mean = values.sum(axis, dtype=np.float64) / count
    if axis is not None:
        mean = np.expand_dims(mean, axis)

    adjusted = values - mean
    if skipna and mask is not None:
        np.putmask(adjusted, mask, 0)
    adjusted2 = adjusted**2
    adjusted4 = adjusted2**2
    m2 = adjusted2.sum(axis, dtype=np.float64)
    m4 = adjusted4.sum(axis, dtype=np.float64)

    with np.errstate(invalid="ignore", divide="ignore"):
        adj = 3 * (count - 1)**2 / ((count - 2) * (count - 3))
        numer = count * (count + 1) * (count - 1) * m4
        denom = (count - 2) * (count - 3) * m2**2

    # floating point error
    #
    # #18044 in _libs/windows.pyx calc_kurt follow this behavior
    # to fix the fperr to treat denom <1e-14 as zero
    numer = _zero_out_fperr(numer)
    denom = _zero_out_fperr(denom)

    if not isinstance(denom, np.ndarray):
        # if ``denom`` is a scalar, check these corner cases first before
        # doing division
        if count < 4:
            return np.nan
        if denom == 0:
            return 0

    with np.errstate(invalid="ignore", divide="ignore"):
        result = numer / denom - adj

    dtype = values.dtype
    if is_float_dtype(dtype):
        result = result.astype(dtype)

    if isinstance(result, np.ndarray):
        result = np.where(denom == 0, 0, result)
        result[count < 4] = np.nan

    return result
Beispiel #39
0
def coerce_to_array(values, dtype, mask=None, copy=False):
    """
    Coerce the input values array to numpy arrays with a mask

    Parameters
    ----------
    values : 1D list-like
    dtype : integer dtype
    mask : boolean 1D array, optional
    copy : boolean, default False
        if True, copy the input

    Returns
    -------
    tuple of (values, mask)
    """
    # if values is integer numpy array, preserve it's dtype
    if dtype is None and hasattr(values, 'dtype'):
        if is_integer_dtype(values.dtype):
            dtype = values.dtype

    if dtype is not None:
        if (isinstance(dtype, string_types)
                and (dtype.startswith("Int") or dtype.startswith("UInt"))):
            # Avoid DeprecationWarning from NumPy about np.dtype("Int64")
            # https://github.com/numpy/numpy/pull/7476
            dtype = dtype.lower()
        if not issubclass(type(dtype), _IntegerDtype):
            try:
                dtype = _dtypes[str(np.dtype(dtype))]
            except KeyError:
                raise ValueError("invalid dtype specified {}".format(dtype))

    if isinstance(values, IntegerArray):
        values, mask = values._data, values._mask
        if dtype is not None:
            values = values.astype(dtype.numpy_dtype, copy=False)

        if copy:
            values = values.copy()
            mask = mask.copy()
        return values, mask

    values = np.array(values, copy=copy)
    if is_object_dtype(values):
        inferred_type = lib.infer_dtype(values)
        if inferred_type is 'mixed' and isna(values).all():
            values = np.empty(len(values))
            values.fill(np.nan)
        elif inferred_type not in [
                'floating', 'integer', 'mixed-integer', 'mixed-integer-float'
        ]:
            raise TypeError("{} cannot be converted to an IntegerDtype".format(
                values.dtype))

    elif not (is_integer_dtype(values) or is_float_dtype(values)):
        raise TypeError("{} cannot be converted to an IntegerDtype".format(
            values.dtype))

    if mask is None:
        mask = isna(values)
    else:
        assert len(mask) == len(values)

    if not values.ndim == 1:
        raise TypeError("values must be a 1D list-like")
    if not mask.ndim == 1:
        raise TypeError("mask must be a 1D list-like")

    # infer dtype if needed
    if dtype is None:
        dtype = np.dtype('int64')
    else:
        dtype = dtype.type

    # if we are float, let's make sure that we can
    # safely cast

    # we copy as need to coerce here
    if mask.any():
        values = values.copy()
        values[mask] = 1
        values = safe_cast(values, dtype, copy=False)
    else:
        values = safe_cast(values, dtype, copy=False)

    return values, mask
Beispiel #40
0
def _get_values(
    values: np.ndarray,
    skipna: bool,
    fill_value: Any = None,
    fill_value_typ: Optional[str] = None,
    mask: Optional[np.ndarray] = None,
) -> Tuple[np.ndarray, Optional[np.ndarray], np.dtype, np.dtype, Any]:
    """
    Utility to get the values view, mask, dtype, dtype_max, and fill_value.

    If both mask and fill_value/fill_value_typ are not None and skipna is True,
    the values array will be copied.

    For input arrays of boolean or integer dtypes, copies will only occur if a
    precomputed mask, a fill_value/fill_value_typ, and skipna=True are
    provided.

    Parameters
    ----------
    values : ndarray
        input array to potentially compute mask for
    skipna : bool
        boolean for whether NaNs should be skipped
    fill_value : Any
        value to fill NaNs with
    fill_value_typ : str
        Set to '+inf' or '-inf' to handle dtype-specific infinities
    mask : Optional[np.ndarray]
        nan-mask if known

    Returns
    -------
    values : ndarray
        Potential copy of input value array
    mask : Optional[ndarray[bool]]
        Mask for values, if deemed necessary to compute
    dtype : np.dtype
        dtype for values
    dtype_max : np.dtype
        platform independent dtype
    fill_value : Any
        fill value used
    """
    # In _get_values is only called from within nanops, and in all cases
    #  with scalar fill_value.  This guarantee is important for the
    #  maybe_upcast_putmask call below
    assert is_scalar(fill_value)
    values = extract_array(values, extract_numpy=True)

    mask = _maybe_get_mask(values, skipna, mask)

    dtype = values.dtype

    if needs_i8_conversion(values.dtype):
        # changing timedelta64/datetime64 to int64 needs to happen after
        #  finding `mask` above
        values = np.asarray(values.view("i8"))

    dtype_ok = _na_ok_dtype(dtype)

    # get our fill value (in case we need to provide an alternative
    # dtype for it)
    fill_value = _get_fill_value(dtype,
                                 fill_value=fill_value,
                                 fill_value_typ=fill_value_typ)

    if skipna and (mask is not None) and (fill_value is not None):
        values = values.copy()
        if dtype_ok and mask.any():
            np.putmask(values, mask, fill_value)

        # promote if needed
        else:
            values, _ = maybe_upcast_putmask(values, mask, fill_value)

    # return a platform independent precision dtype
    dtype_max = dtype
    if is_integer_dtype(dtype) or is_bool_dtype(dtype):
        dtype_max = np.dtype(np.int64)
    elif is_float_dtype(dtype):
        dtype_max = np.dtype(np.float64)

    return values, mask, dtype, dtype_max, fill_value
Beispiel #41
0
def nanmedian(values, axis=None, skipna=True, mask=None):
    """
    Parameters
    ----------
    values : ndarray
    axis: int, optional
    skipna : bool, default True
    mask : ndarray[bool], optional
        nan-mask if known

    Returns
    -------
    result : float
        Unless input is a float array, in which case use the same
        precision as the input array.

    Examples
    --------
    >>> import pandas.core.nanops as nanops
    >>> s = pd.Series([1, np.nan, 2, 2])
    >>> nanops.nanmedian(s)
    2.0
    """
    def get_median(x):
        mask = notna(x)
        if not skipna and not mask.all():
            return np.nan
        return np.nanmedian(x[mask])

    values, mask, dtype, _, _ = _get_values(values, skipna, mask=mask)
    if not is_float_dtype(values.dtype):
        try:
            values = values.astype("f8")
        except ValueError as err:
            # e.g. "could not convert string to float: 'a'"
            raise TypeError from err
        if mask is not None:
            values[mask] = np.nan

    if axis is None:
        values = values.ravel()

    notempty = values.size

    # an array from a frame
    if values.ndim > 1:

        # there's a non-empty array to apply over otherwise numpy raises
        if notempty:
            if not skipna:
                return _wrap_results(
                    np.apply_along_axis(get_median, axis, values), dtype)

            # fastpath for the skipna case
            return _wrap_results(np.nanmedian(values, axis), dtype)

        # must return the correct shape, but median is not defined for the
        # empty set so return nans of shape "everything but the passed axis"
        # since "axis" is where the reduction would occur if we had a nonempty
        # array
        shp = np.array(values.shape)
        dims = np.arange(values.ndim)
        ret = np.empty(shp[dims != axis])
        ret.fill(np.nan)
        return _wrap_results(ret, dtype)

    # otherwise return a scalar value
    return _wrap_results(get_median(values) if notempty else np.nan, dtype)
Beispiel #42
0
    def _ea_wrap_cython_operation(
        self,
        cy_op: WrappedCythonOp,
        kind: str,
        values,
        how: str,
        axis: int,
        min_count: int = -1,
        **kwargs,
    ) -> ArrayLike:
        """
        If we have an ExtensionArray, unwrap, call _cython_operation, and
        re-wrap if appropriate.
        """
        # TODO: general case implementation overridable by EAs.
        orig_values = values

        if is_datetime64tz_dtype(values.dtype) or is_period_dtype(
                values.dtype):
            # All of the functions implemented here are ordinal, so we can
            #  operate on the tz-naive equivalents
            npvalues = values.view("M8[ns]")
            res_values = self._cython_operation(kind, npvalues, how, axis,
                                                min_count, **kwargs)
            if how in ["rank"]:
                # i.e. how in WrappedCythonOp.cast_blocklist, since
                #  other cast_blocklist methods dont go through cython_operation
                # preserve float64 dtype
                return res_values

            res_values = res_values.astype("i8", copy=False)
            result = type(orig_values)(res_values, dtype=orig_values.dtype)
            return result

        elif is_integer_dtype(values.dtype) or is_bool_dtype(values.dtype):
            # IntegerArray or BooleanArray
            values = values.to_numpy("float64", na_value=np.nan)
            res_values = self._cython_operation(kind, values, how, axis,
                                                min_count, **kwargs)
            if how in ["rank"]:
                # i.e. how in WrappedCythonOp.cast_blocklist, since
                #  other cast_blocklist methods dont go through cython_operation
                return res_values

            dtype = cy_op.get_result_dtype(orig_values.dtype)
            # error: Item "dtype[Any]" of "Union[dtype[Any], ExtensionDtype]"
            # has no attribute "construct_array_type"
            cls = dtype.construct_array_type()  # type: ignore[union-attr]
            return cls._from_sequence(res_values, dtype=dtype)

        elif is_float_dtype(values.dtype):
            # FloatingArray
            values = values.to_numpy(values.dtype.numpy_dtype, na_value=np.nan)
            res_values = self._cython_operation(kind, values, how, axis,
                                                min_count, **kwargs)
            if how in ["rank"]:
                # i.e. how in WrappedCythonOp.cast_blocklist, since
                #  other cast_blocklist methods dont go through cython_operation
                return res_values

            dtype = cy_op.get_result_dtype(orig_values.dtype)
            # error: Item "dtype[Any]" of "Union[dtype[Any], ExtensionDtype]"
            # has no attribute "construct_array_type"
            cls = dtype.construct_array_type()  # type: ignore[union-attr]
            return cls._from_sequence(res_values, dtype=dtype)

        raise NotImplementedError(
            f"function is not implemented for this dtype: {values.dtype}")
Beispiel #43
0
    def __floordiv__(self, other):

        if is_scalar(other):
            if isinstance(other, self._recognized_scalars):
                other = Timedelta(other)
                if other is NaT:
                    # treat this specifically as timedelta-NaT
                    result = np.empty(self.shape, dtype=np.float64)
                    result.fill(np.nan)
                    return result

                # dispatch to Timedelta implementation
                result = other.__rfloordiv__(self._data)
                return result

            # at this point we should only have numeric scalars; anything
            #  else will raise
            result = self.asi8 // other
            result[self._isnan] = iNaT
            freq = None
            if self.freq is not None:
                # Note: freq gets division, not floor-division
                freq = self.freq / other
                if freq.nanos == 0 and self.freq.nanos != 0:
                    # e.g. if self.freq is Nano(1) then dividing by 2
                    #  rounds down to zero
                    freq = None
            return type(self)(result.view("m8[ns]"), freq=freq)

        if not hasattr(other, "dtype"):
            # list, tuple
            other = np.array(other)
        if len(other) != len(self):
            raise ValueError("Cannot divide with unequal lengths")

        elif is_timedelta64_dtype(other.dtype):
            other = type(self)(other)

            # numpy timedelta64 does not natively support floordiv, so operate
            #  on the i8 values
            result = self.asi8 // other.asi8
            mask = self._isnan | other._isnan
            if mask.any():
                result = result.astype(np.float64)
                result[mask] = np.nan
            return result

        elif is_object_dtype(other.dtype):
            result = [self[n] // other[n] for n in range(len(self))]
            result = np.array(result)
            if lib.infer_dtype(result, skipna=False) == "timedelta":
                result, _ = sequence_to_td64ns(result)
                return type(self)(result)
            return result

        elif is_integer_dtype(other.dtype) or is_float_dtype(other.dtype):
            result = self._data // other
            return type(self)(result)

        else:
            dtype = getattr(other, "dtype", type(other).__name__)
            raise TypeError(f"Cannot divide {dtype} by {type(self).__name__}")
Beispiel #44
0
    def __floordiv__(self, other):

        if is_scalar(other):
            if isinstance(other, self._recognized_scalars):
                other = Timedelta(other)
                # mypy assumes that __new__ returns an instance of the class
                # github.com/python/mypy/issues/1020
                if cast("Timedelta | NaTType", other) is NaT:
                    # treat this specifically as timedelta-NaT
                    result = np.empty(self.shape, dtype=np.float64)
                    result.fill(np.nan)
                    return result

                # dispatch to Timedelta implementation
                return other.__rfloordiv__(self._ndarray)

            # at this point we should only have numeric scalars; anything
            #  else will raise
            result = self._ndarray // other
            freq = None
            if self.freq is not None:
                # Note: freq gets division, not floor-division
                freq = self.freq / other
                if freq.nanos == 0 and self.freq.nanos != 0:
                    # e.g. if self.freq is Nano(1) then dividing by 2
                    #  rounds down to zero
                    freq = None
            return type(self)(result, freq=freq)

        if not hasattr(other, "dtype"):
            # list, tuple
            other = np.array(other)
        if len(other) != len(self):
            raise ValueError("Cannot divide with unequal lengths")

        elif is_timedelta64_dtype(other.dtype):
            other = type(self)(other)

            # numpy timedelta64 does not natively support floordiv, so operate
            #  on the i8 values
            result = self.asi8 // other.asi8
            mask = self._isnan | other._isnan
            if mask.any():
                result = result.astype(np.float64)
                np.putmask(result, mask, np.nan)
            return result

        elif is_object_dtype(other.dtype):
            # error: Incompatible types in assignment (expression has type
            # "List[Any]", variable has type "ndarray")
            srav = self.ravel()
            orav = other.ravel()
            res_list = [srav[n] // orav[n] for n in range(len(srav))]
            result_flat = np.asarray(res_list)
            inferred = lib.infer_dtype(result_flat, skipna=False)

            result = result_flat.reshape(self.shape)

            if inferred == "timedelta":
                result, _ = sequence_to_td64ns(result)
                return type(self)(result)
            if inferred == "datetime":
                # GH#39750 occurs when result is all-NaT, which in this
                #  case should be interpreted as td64nat. This can only
                #  occur when self is all-td64nat
                return self * np.nan
            return result

        elif is_integer_dtype(other.dtype) or is_float_dtype(other.dtype):
            result = self._ndarray // other
            return type(self)(result)

        else:
            dtype = getattr(other, "dtype", type(other).__name__)
            raise TypeError(f"Cannot divide {dtype} by {type(self).__name__}")
Beispiel #45
0
def sanitize_array(
    data, index, dtype=None, copy: bool = False, raise_cast_failure: bool = False
):
    """
    Sanitize input data to an ndarray, copy if specified, coerce to the
    dtype if specified.
    """
    if dtype is not None:
        dtype = pandas_dtype(dtype)

    if isinstance(data, ma.MaskedArray):
        mask = ma.getmaskarray(data)
        if mask.any():
            data, fill_value = maybe_upcast(data, copy=True)
            data.soften_mask()  # set hardmask False if it was True
            data[mask] = fill_value
        else:
            data = data.copy()

    # extract ndarray or ExtensionArray, ensure we have no PandasArray
    data = extract_array(data, extract_numpy=True)

    # GH#846
    if isinstance(data, np.ndarray):

        if dtype is not None and is_float_dtype(data.dtype) and is_integer_dtype(dtype):
            # possibility of nan -> garbage
            try:
                subarr = _try_cast(data, dtype, copy, True)
            except ValueError:
                if copy:
                    subarr = data.copy()
                else:
                    subarr = np.array(data, copy=False)
        else:
            # we will try to copy be-definition here
            subarr = _try_cast(data, dtype, copy, raise_cast_failure)

    elif isinstance(data, ABCExtensionArray):
        # it is already ensured above this is not a PandasArray
        subarr = data

        if dtype is not None:
            subarr = subarr.astype(dtype, copy=copy)
        elif copy:
            subarr = subarr.copy()
        return subarr

    elif isinstance(data, (list, tuple)) and len(data) > 0:
        if dtype is not None:
            subarr = _try_cast(data, dtype, copy, raise_cast_failure)
        else:
            subarr = maybe_convert_platform(data)

        subarr = maybe_cast_to_datetime(subarr, dtype)

    elif isinstance(data, range):
        # GH#16804
        arr = np.arange(data.start, data.stop, data.step, dtype="int64")
        subarr = _try_cast(arr, dtype, copy, raise_cast_failure)
    else:
        subarr = _try_cast(data, dtype, copy, raise_cast_failure)

    # scalar like, GH
    if getattr(subarr, "ndim", 0) == 0:
        if isinstance(data, list):  # pragma: no cover
            subarr = np.array(data, dtype=object)
        elif index is not None:
            value = data

            # figure out the dtype from the value (upcast if necessary)
            if dtype is None:
                dtype, value = infer_dtype_from_scalar(value)
            else:
                # need to possibly convert the value here
                value = maybe_cast_to_datetime(value, dtype)

            subarr = construct_1d_arraylike_from_scalar(value, len(index), dtype)

        else:
            return subarr.item()

    # the result that we want
    elif subarr.ndim == 1:
        if index is not None:

            # a 1-element ndarray
            if len(subarr) != len(index) and len(subarr) == 1:
                subarr = construct_1d_arraylike_from_scalar(
                    subarr[0], len(index), subarr.dtype
                )

    elif subarr.ndim > 1:
        if isinstance(data, np.ndarray):
            raise Exception("Data must be 1-dimensional")
        else:
            subarr = com.asarray_tuplesafe(data, dtype=dtype)

    if not (is_extension_array_dtype(subarr.dtype) or is_extension_array_dtype(dtype)):
        # This is to prevent mixed-type Series getting all casted to
        # NumPy string type, e.g. NaN --> '-1#IND'.
        if issubclass(subarr.dtype.type, str):
            # GH#16605
            # If not empty convert the data to dtype
            # GH#19853: If data is a scalar, subarr has already the result
            if not lib.is_scalar(data):
                if not np.all(isna(data)):
                    data = np.array(data, dtype=dtype, copy=False)
                subarr = np.array(data, dtype=object, copy=copy)

        if is_object_dtype(subarr.dtype) and not is_object_dtype(dtype):
            inferred = lib.infer_dtype(subarr, skipna=False)
            if inferred == "period":
                from pandas.core.arrays import period_array

                try:
                    subarr = period_array(subarr)
                except IncompatibleFrequency:
                    pass

    return subarr
Beispiel #46
0
    def test_constructor(self):

        exp_arr = np.array(["a", "b", "c", "a", "b", "c"], dtype=np.object_)
        c1 = Categorical(exp_arr)
        tm.assert_numpy_array_equal(c1.__array__(), exp_arr)
        c2 = Categorical(exp_arr, categories=["a", "b", "c"])
        tm.assert_numpy_array_equal(c2.__array__(), exp_arr)
        c2 = Categorical(exp_arr, categories=["c", "b", "a"])
        tm.assert_numpy_array_equal(c2.__array__(), exp_arr)

        # categories must be unique
        msg = "Categorical categories must be unique"
        with pytest.raises(ValueError, match=msg):
            Categorical([1, 2], [1, 2, 2])

        with pytest.raises(ValueError, match=msg):
            Categorical(["a", "b"], ["a", "b", "b"])

        # The default should be unordered
        c1 = Categorical(["a", "b", "c", "a"])
        assert not c1.ordered

        # Categorical as input
        c1 = Categorical(["a", "b", "c", "a"])
        c2 = Categorical(c1)
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "b", "c", "d"])
        c2 = Categorical(c1)
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "c", "b"])
        c2 = Categorical(c1)
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "c", "b"])
        c2 = Categorical(c1, categories=["a", "b", "c"])
        tm.assert_numpy_array_equal(c1.__array__(), c2.__array__())
        tm.assert_index_equal(c2.categories, Index(["a", "b", "c"]))

        # Series of dtype category
        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "b", "c", "d"])
        c2 = Categorical(Series(c1))
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "c", "b"])
        c2 = Categorical(Series(c1))
        tm.assert_categorical_equal(c1, c2)

        # Series
        c1 = Categorical(["a", "b", "c", "a"])
        c2 = Categorical(Series(["a", "b", "c", "a"]))
        tm.assert_categorical_equal(c1, c2)

        c1 = Categorical(["a", "b", "c", "a"], categories=["a", "b", "c", "d"])
        c2 = Categorical(Series(["a", "b", "c", "a"]), categories=["a", "b", "c", "d"])
        tm.assert_categorical_equal(c1, c2)

        # This should result in integer categories, not float!
        cat = Categorical([1, 2, 3, np.nan], categories=[1, 2, 3])
        assert is_integer_dtype(cat.categories)

        # https://github.com/pandas-dev/pandas/issues/3678
        cat = Categorical([np.nan, 1, 2, 3])
        assert is_integer_dtype(cat.categories)

        # this should result in floats
        cat = Categorical([np.nan, 1, 2.0, 3])
        assert is_float_dtype(cat.categories)

        cat = Categorical([np.nan, 1.0, 2.0, 3.0])
        assert is_float_dtype(cat.categories)

        # This doesn't work -> this would probably need some kind of "remember
        # the original type" feature to try to cast the array interface result
        # to...

        # vals = np.asarray(cat[cat.notna()])
        # assert is_integer_dtype(vals)

        # corner cases
        cat = Categorical([1])
        assert len(cat.categories) == 1
        assert cat.categories[0] == 1
        assert len(cat.codes) == 1
        assert cat.codes[0] == 0

        cat = Categorical(["a"])
        assert len(cat.categories) == 1
        assert cat.categories[0] == "a"
        assert len(cat.codes) == 1
        assert cat.codes[0] == 0

        with tm.assert_produces_warning(FutureWarning):
            # GH#38433
            cat = Categorical(1)
        assert len(cat.categories) == 1
        assert cat.categories[0] == 1
        assert len(cat.codes) == 1
        assert cat.codes[0] == 0
        # two arrays
        #  - when the first is an integer dtype and the second is not
        #  - when the resulting codes are all -1/NaN
        with tm.assert_produces_warning(None):
            c_old = Categorical([0, 1, 2, 0, 1, 2], categories=["a", "b", "c"])

        with tm.assert_produces_warning(None):
            c_old = Categorical([0, 1, 2, 0, 1, 2], categories=[3, 4, 5])  # noqa

        # the next one are from the old docs
        with tm.assert_produces_warning(None):
            c_old2 = Categorical([0, 1, 2, 0, 1, 2], [1, 2, 3])  # noqa
            cat = Categorical([1, 2], categories=[1, 2, 3])

        # this is a legitimate constructor
        with tm.assert_produces_warning(None):
            c = Categorical(  # noqa
                np.array([], dtype="int64"), categories=[3, 2, 1], ordered=True
            )
Beispiel #47
0
def putmask_smart(values: np.ndarray, mask: np.ndarray, new) -> np.ndarray:
    """
    Return a new ndarray, try to preserve dtype if possible.

    Parameters
    ----------
    values : np.ndarray
        `values`, updated in-place.
    mask : np.ndarray[bool]
        Applies to both sides (array like).
    new : `new values` either scalar or an array like aligned with `values`

    Returns
    -------
    values : ndarray with updated values
        this *may* be a copy of the original

    See Also
    --------
    ndarray.putmask
    """
    # we cannot use np.asarray() here as we cannot have conversions
    # that numpy does when numeric are mixed with strings

    # n should be the length of the mask or a scalar here
    if not is_list_like(new):
        new = np.repeat(new, len(mask))

    # see if we are only masking values that if putted
    # will work in the current dtype
    try:
        nn = new[mask]
    except TypeError:
        # TypeError: only integer scalar arrays can be converted to a scalar index
        pass
    else:
        # make sure that we have a nullable type if we have nulls
        if not isna_compat(values, nn[0]):
            pass
        elif not (is_float_dtype(nn.dtype) or is_integer_dtype(nn.dtype)):
            # only compare integers/floats
            pass
        elif not (is_float_dtype(values.dtype)
                  or is_integer_dtype(values.dtype)):
            # only compare integers/floats
            pass
        else:

            # we ignore ComplexWarning here
            with warnings.catch_warnings(record=True):
                warnings.simplefilter("ignore", np.ComplexWarning)
                nn_at = nn.astype(values.dtype)

            comp = nn == nn_at
            if is_list_like(comp) and comp.all():
                nv = values.copy()
                nv[mask] = nn_at
                return nv

    new = np.asarray(new)

    if values.dtype.kind == new.dtype.kind:
        # preserves dtype if possible
        return _putmask_preserve(values, new, mask)

    dtype = find_common_type([values.dtype, new.dtype])
    values = values.astype(dtype)

    return _putmask_preserve(values, new, mask)
Beispiel #48
0
def sequence_to_td64ns(data, copy=False, unit=None, errors="raise"):
    """
    Parameters
    ----------
    data : list-like
    copy : bool, default False
    unit : str, optional
        The timedelta unit to treat integers as multiples of. For numeric
        data this defaults to ``'ns'``.
        Must be un-specified if the data contains a str and ``errors=="raise"``.
    errors : {"raise", "coerce", "ignore"}, default "raise"
        How to handle elements that cannot be converted to timedelta64[ns].
        See ``pandas.to_timedelta`` for details.

    Returns
    -------
    converted : numpy.ndarray
        The sequence converted to a numpy array with dtype ``timedelta64[ns]``.
    inferred_freq : Tick or None
        The inferred frequency of the sequence.

    Raises
    ------
    ValueError : Data cannot be converted to timedelta64[ns].

    Notes
    -----
    Unlike `pandas.to_timedelta`, if setting ``errors=ignore`` will not cause
    errors to be ignored; they are caught and subsequently ignored at a
    higher level.
    """
    inferred_freq = None
    if unit is not None:
        unit = parse_timedelta_unit(unit)

    # Unwrap whatever we have into a np.ndarray
    if not hasattr(data, "dtype"):
        # e.g. list, tuple
        if np.ndim(data) == 0:
            # i.e. generator
            data = list(data)
        data = np.array(data, copy=False)
    elif isinstance(data, ABCSeries):
        data = data._values
    elif isinstance(data, (ABCTimedeltaIndex, TimedeltaArray)):
        inferred_freq = data.freq
        data = data._data
    elif isinstance(data, IntegerArray):
        data = data.to_numpy("int64", na_value=tslibs.iNaT)
    elif is_categorical_dtype(data.dtype):
        data = data.categories.take(data.codes, fill_value=NaT)._values
        copy = False

    # Convert whatever we have into timedelta64[ns] dtype
    if is_object_dtype(data.dtype) or is_string_dtype(data.dtype):
        # no need to make a copy, need to convert if string-dtyped
        data = objects_to_td64ns(data, unit=unit, errors=errors)
        copy = False

    elif is_integer_dtype(data.dtype):
        # treat as multiples of the given unit
        data, copy_made = ints_to_td64ns(data, unit=unit)
        copy = copy and not copy_made

    elif is_float_dtype(data.dtype):
        # cast the unit, multiply base/frac separately
        # to avoid precision issues from float -> int
        mask = np.isnan(data)
        m, p = precision_from_unit(unit or "ns")
        base = data.astype(np.int64)
        frac = data - base
        if p:
            frac = np.round(frac, p)
        data = (base * m + (frac * m).astype(np.int64)).view("timedelta64[ns]")
        data[mask] = iNaT
        copy = False

    elif is_timedelta64_dtype(data.dtype):
        if data.dtype != TD64NS_DTYPE:
            # non-nano unit
            # TODO: watch out for overflows
            data = data.astype(TD64NS_DTYPE)
            copy = False

    else:
        # This includes datetime64-dtype, see GH#23539, GH#29794
        raise TypeError(
            f"dtype {data.dtype} cannot be converted to timedelta64[ns]")

    data = np.array(data, copy=copy)

    assert data.dtype == "m8[ns]", data
    return data, inferred_freq
Beispiel #49
0
def period_array(
    data: Sequence[Period | str | None] | AnyArrayLike,
    freq: str | Tick | None = None,
    copy: bool = False,
) -> PeriodArray:
    """
    Construct a new PeriodArray from a sequence of Period scalars.

    Parameters
    ----------
    data : Sequence of Period objects
        A sequence of Period objects. These are required to all have
        the same ``freq.`` Missing values can be indicated by ``None``
        or ``pandas.NaT``.
    freq : str, Tick, or Offset
        The frequency of every element of the array. This can be specified
        to avoid inferring the `freq` from `data`.
    copy : bool, default False
        Whether to ensure a copy of the data is made.

    Returns
    -------
    PeriodArray

    See Also
    --------
    PeriodArray
    pandas.PeriodIndex

    Examples
    --------
    >>> period_array([pd.Period('2017', freq='A'),
    ...               pd.Period('2018', freq='A')])
    <PeriodArray>
    ['2017', '2018']
    Length: 2, dtype: period[A-DEC]

    >>> period_array([pd.Period('2017', freq='A'),
    ...               pd.Period('2018', freq='A'),
    ...               pd.NaT])
    <PeriodArray>
    ['2017', '2018', 'NaT']
    Length: 3, dtype: period[A-DEC]

    Integers that look like years are handled

    >>> period_array([2000, 2001, 2002], freq='D')
    <PeriodArray>
    ['2000-01-01', '2001-01-01', '2002-01-01']
    Length: 3, dtype: period[D]

    Datetime-like strings may also be passed

    >>> period_array(['2000-Q1', '2000-Q2', '2000-Q3', '2000-Q4'], freq='Q')
    <PeriodArray>
    ['2000Q1', '2000Q2', '2000Q3', '2000Q4']
    Length: 4, dtype: period[Q-DEC]
    """
    data_dtype = getattr(data, "dtype", None)

    if is_datetime64_dtype(data_dtype):
        return PeriodArray._from_datetime64(data, freq)
    if is_period_dtype(data_dtype):
        return PeriodArray(data, freq=freq)

    # other iterable of some kind
    if not isinstance(data, (np.ndarray, list, tuple, ABCSeries)):
        data = list(data)

    arrdata = np.asarray(data)

    dtype: PeriodDtype | None
    if freq:
        dtype = PeriodDtype(freq)
    else:
        dtype = None

    if is_float_dtype(arrdata) and len(arrdata) > 0:
        raise TypeError(
            "PeriodIndex does not allow floating point in construction")

    if is_integer_dtype(arrdata.dtype):
        arr = arrdata.astype(np.int64, copy=False)
        # error: Argument 2 to "from_ordinals" has incompatible type "Union[str,
        # Tick, None]"; expected "Union[timedelta, BaseOffset, str]"
        ordinals = libperiod.from_ordinals(arr, freq)  # type: ignore[arg-type]
        return PeriodArray(ordinals, dtype=dtype)

    data = ensure_object(arrdata)

    return PeriodArray._from_sequence(data, dtype=dtype)
Beispiel #50
0
        def __sub__(self, other):
            from pandas import Index

            other = lib.item_from_zerodim(other)
            if isinstance(other, (ABCSeries, ABCDataFrame)):
                return NotImplemented

            # scalar others
            elif other is NaT:
                result = self._sub_nat()
            elif isinstance(other, (Tick, timedelta, np.timedelta64)):
                result = self._add_delta(-other)
            elif isinstance(other, DateOffset):
                # specifically _not_ a Tick
                result = self._add_offset(-other)
            elif isinstance(other, (datetime, np.datetime64)):
                result = self._sub_datelike(other)
            elif is_integer(other):
                # This check must come after the check for np.timedelta64
                # as is_integer returns True for these
                result = self.shift(-other)
            elif isinstance(other, Period):
                result = self._sub_period(other)

            # array-like others
            elif is_timedelta64_dtype(other):
                # TimedeltaIndex, ndarray[timedelta64]
                result = self._add_delta(-other)
            elif is_offsetlike(other):
                # Array/Index of DateOffset objects
                result = self._addsub_offset_array(other, operator.sub)
            elif is_datetime64_dtype(other) or is_datetime64tz_dtype(other):
                # DatetimeIndex, ndarray[datetime64]
                result = self._sub_datelike(other)
            elif is_period_dtype(other):
                # PeriodIndex
                result = self._sub_period_array(other)
            elif is_integer_dtype(other):
                result = self._addsub_int_array(other, operator.sub)
            elif isinstance(other, Index):
                raise TypeError("cannot subtract {cls} and {typ}"
                                .format(cls=type(self).__name__,
                                        typ=type(other).__name__))
            elif is_float_dtype(other):
                # Explicitly catch invalid dtypes
                raise TypeError("cannot subtract {dtype}-dtype from {cls}"
                                .format(dtype=other.dtype,
                                        cls=type(self).__name__))
            elif is_categorical_dtype(other):
                # Categorical op will raise; defer explicitly
                return NotImplemented
            else:  # pragma: no cover
                return NotImplemented

            if result is NotImplemented:
                return NotImplemented
            elif not isinstance(result, Index):
                # Index.__new__ will choose appropriate subclass for dtype
                result = Index(result)
            res_name = ops.get_op_result_name(self, other)
            result.name = res_name
            return result
Beispiel #51
0
def nanmean(
    values: np.ndarray,
    *,
    axis: Optional[int] = None,
    skipna: bool = True,
    mask: Optional[np.ndarray] = None,
) -> float:
    """
    Compute the mean of the element along an axis ignoring NaNs

    Parameters
    ----------
    values : ndarray
    axis: int, optional
    skipna : bool, default True
    mask : ndarray[bool], optional
        nan-mask if known

    Returns
    -------
    float
        Unless input is a float array, in which case use the same
        precision as the input array.

    Examples
    --------
    >>> import pandas.core.nanops as nanops
    >>> s = pd.Series([1, 2, np.nan])
    >>> nanops.nanmean(s)
    1.5
    """
    orig_values = values

    values, mask, dtype, dtype_max, _ = _get_values(
        values, skipna, fill_value=0, mask=mask
    )
    dtype_sum = dtype_max
    dtype_count = np.float64

    # not using needs_i8_conversion because that includes period
    datetimelike = False
    if dtype.kind in ["m", "M"]:
        datetimelike = True
        dtype_sum = np.float64
    elif is_integer_dtype(dtype):
        dtype_sum = np.float64
    elif is_float_dtype(dtype):
        dtype_sum = dtype
        dtype_count = dtype

    count = _get_counts(values.shape, mask, axis, dtype=dtype_count)
    the_sum = _ensure_numeric(values.sum(axis, dtype=dtype_sum))

    if axis is not None and getattr(the_sum, "ndim", False):
        count = cast(np.ndarray, count)
        with np.errstate(all="ignore"):
            # suppress division by zero warnings
            the_mean = the_sum / count
        ct_mask = count == 0
        if ct_mask.any():
            the_mean[ct_mask] = np.nan
    else:
        the_mean = the_sum / count if count > 0 else np.nan

    the_mean = _wrap_results(the_mean, dtype)
    if datetimelike and not skipna:
        the_mean = _mask_datetimelike_result(the_mean, axis, mask, orig_values)
    return the_mean
Beispiel #52
0
def sanitize_array(
    data,
    index: Index | None,
    dtype: DtypeObj | None = None,
    copy: bool = False,
    raise_cast_failure: bool = True,
    *,
    allow_2d: bool = False,
) -> ArrayLike:
    """
    Sanitize input data to an ndarray or ExtensionArray, copy if specified,
    coerce to the dtype if specified.

    Parameters
    ----------
    data : Any
    index : Index or None, default None
    dtype : np.dtype, ExtensionDtype, or None, default None
    copy : bool, default False
    raise_cast_failure : bool, default True
    allow_2d : bool, default False
        If False, raise if we have a 2D Arraylike.

    Returns
    -------
    np.ndarray or ExtensionArray

    Notes
    -----
    raise_cast_failure=False is only intended to be True when called from the
    DataFrame constructor, as the dtype keyword there may be interpreted as only
    applying to a subset of columns, see GH#24435.
    """
    if isinstance(data, ma.MaskedArray):
        data = sanitize_masked_array(data)

    if isinstance(dtype, PandasDtype):
        # Avoid ending up with a PandasArray
        dtype = dtype.numpy_dtype

    # extract ndarray or ExtensionArray, ensure we have no PandasArray
    data = extract_array(data, extract_numpy=True)

    if isinstance(data, np.ndarray) and data.ndim == 0:
        if dtype is None:
            dtype = data.dtype
        data = lib.item_from_zerodim(data)
    elif isinstance(data, range):
        # GH#16804
        data = range_to_ndarray(data)
        copy = False

    if not is_list_like(data):
        if index is None:
            raise ValueError("index must be specified when data is not list-like")
        data = construct_1d_arraylike_from_scalar(data, len(index), dtype)
        return data

    # GH#846
    if isinstance(data, np.ndarray):
        if isinstance(data, np.matrix):
            data = data.A

        if dtype is not None and is_float_dtype(data.dtype) and is_integer_dtype(dtype):
            # possibility of nan -> garbage
            try:
                subarr = _try_cast(data, dtype, copy, True)
            except IntCastingNaNError:
                warnings.warn(
                    "In a future version, passing float-dtype values containing NaN "
                    "and an integer dtype will raise IntCastingNaNError "
                    "(subclass of ValueError) instead of silently ignoring the "
                    "passed dtype. To retain the old behavior, call Series(arr) or "
                    "DataFrame(arr) without passing a dtype.",
                    FutureWarning,
                    stacklevel=find_stack_level(),
                )
                subarr = np.array(data, copy=copy)
            except ValueError:
                if not raise_cast_failure:
                    # i.e. called via DataFrame constructor
                    warnings.warn(
                        "In a future version, passing float-dtype values and an "
                        "integer dtype to DataFrame will retain floating dtype "
                        "if they cannot be cast losslessly (matching Series behavior). "
                        "To retain the old behavior, use DataFrame(data).astype(dtype)",
                        FutureWarning,
                        stacklevel=find_stack_level(),
                    )
                    # GH#40110 until the deprecation is enforced, we _dont_
                    #  ignore the dtype for DataFrame, and _do_ cast even though
                    #  it is lossy.
                    dtype = cast(np.dtype, dtype)
                    return np.array(data, dtype=dtype, copy=copy)
                subarr = np.array(data, copy=copy)
        else:
            # we will try to copy by-definition here
            subarr = _try_cast(data, dtype, copy, raise_cast_failure)

    elif isinstance(data, ABCExtensionArray):
        # it is already ensured above this is not a PandasArray
        subarr = data

        if dtype is not None:
            subarr = subarr.astype(dtype, copy=copy)
        elif copy:
            subarr = subarr.copy()

    else:
        if isinstance(data, (set, frozenset)):
            # Raise only for unordered sets, e.g., not for dict_keys
            raise TypeError(f"'{type(data).__name__}' type is unordered")

        # materialize e.g. generators, convert e.g. tuples, abc.ValueView
        if hasattr(data, "__array__"):
            # e.g. dask array GH#38645
            data = np.asarray(data)
        else:
            data = list(data)

        if dtype is not None or len(data) == 0:
            try:
                subarr = _try_cast(data, dtype, copy, raise_cast_failure)
            except ValueError:
                casted = np.array(data, copy=False)
                if casted.dtype.kind == "f" and is_integer_dtype(dtype):
                    # GH#40110 match the behavior we have if we passed
                    #  a ndarray[float] to begin with
                    return sanitize_array(
                        casted,
                        index,
                        dtype,
                        copy=False,
                        raise_cast_failure=raise_cast_failure,
                        allow_2d=allow_2d,
                    )
                else:
                    raise
        else:
            subarr = maybe_convert_platform(data)
            if subarr.dtype == object:
                subarr = cast(np.ndarray, subarr)
                subarr = maybe_infer_to_datetimelike(subarr)

    subarr = _sanitize_ndim(subarr, data, dtype, index, allow_2d=allow_2d)

    if isinstance(subarr, np.ndarray):
        # at this point we should have dtype be None or subarr.dtype == dtype
        dtype = cast(np.dtype, dtype)
        subarr = _sanitize_str_dtypes(subarr, data, dtype, copy)

    return subarr
Beispiel #53
0
def array_equivalent(left, right, strict_nan: bool = False) -> bool:
    """
    True if two arrays, left and right, have equal non-NaN elements, and NaNs
    in corresponding locations.  False otherwise. It is assumed that left and
    right are NumPy arrays of the same dtype. The behavior of this function
    (particularly with respect to NaNs) is not defined if the dtypes are
    different.

    Parameters
    ----------
    left, right : ndarrays
    strict_nan : bool, default False
        If True, consider NaN and None to be different.

    Returns
    -------
    b : bool
        Returns True if the arrays are equivalent.

    Examples
    --------
    >>> array_equivalent(
    ...     np.array([1, 2, np.nan]),
    ...     np.array([1, 2, np.nan]))
    True
    >>> array_equivalent(
    ...     np.array([1, np.nan, 2]),
    ...     np.array([1, 2, np.nan]))
    False
    """
    left, right = np.asarray(left), np.asarray(right)

    # shape compat
    if left.shape != right.shape:
        return False

    # Object arrays can contain None, NaN and NaT.
    # string dtypes must be come to this path for NumPy 1.7.1 compat
    if is_string_dtype(left) or is_string_dtype(right):

        if not strict_nan:
            # isna considers NaN and None to be equivalent.
            return lib.array_equivalent_object(
                ensure_object(left.ravel()), ensure_object(right.ravel())
            )

        for left_value, right_value in zip(left, right):
            if left_value is NaT and right_value is not NaT:
                return False

            elif left_value is libmissing.NA and right_value is not libmissing.NA:
                return False

            elif isinstance(left_value, float) and np.isnan(left_value):
                if not isinstance(right_value, float) or not np.isnan(right_value):
                    return False
            else:
                try:
                    if np.any(np.asarray(left_value != right_value)):
                        return False
                except TypeError as err:
                    if "Cannot compare tz-naive" in str(err):
                        # tzawareness compat failure, see GH#28507
                        return False
                    elif "boolean value of NA is ambiguous" in str(err):
                        return False
                    raise
        return True

    # NaNs can occur in float and complex arrays.
    if is_float_dtype(left.dtype) or is_complex_dtype(left.dtype):

        # empty
        if not (np.prod(left.shape) and np.prod(right.shape)):
            return True
        return ((left == right) | (isna(left) & isna(right))).all()

    elif is_datetimelike_v_numeric(left, right):
        # GH#29553 avoid numpy deprecation warning
        return False

    elif needs_i8_conversion(left.dtype) or needs_i8_conversion(right.dtype):
        # datetime64, timedelta64, Period
        if not is_dtype_equal(left.dtype, right.dtype):
            return False

        left = left.view("i8")
        right = right.view("i8")

    # if we have structured dtypes, compare first
    if left.dtype.type is np.void or right.dtype.type is np.void:
        if left.dtype != right.dtype:
            return False

    return np.array_equal(left, right)
Beispiel #54
0
def _get_values(values: np.ndarray, skipna: bool, fill_value: Any = None,
                fill_value_typ: Optional[str] = None,
                mask: Optional[np.ndarray] = None
                ) -> Tuple[np.ndarray, Optional[np.ndarray], np.dtype,
                           np.dtype, Any]:
    """ Utility to get the values view, mask, dtype, dtype_max, and fill_value.

    If both mask and fill_value/fill_value_typ are not None and skipna is True,
    the values array will be copied.

    For input arrays of boolean or integer dtypes, copies will only occur if a
    precomputed mask, a fill_value/fill_value_typ, and skipna=True are
    provided.

    Parameters
    ----------
    values : ndarray
        input array to potentially compute mask for
    skipna : bool
        boolean for whether NaNs should be skipped
    fill_value : Any
        value to fill NaNs with
    fill_value_typ : str
        Set to '+inf' or '-inf' to handle dtype-specific infinities
    mask : Optional[np.ndarray]
        nan-mask if known

    Returns
    -------
    values : ndarray
        Potential copy of input value array
    mask : Optional[ndarray[bool]]
        Mask for values, if deemed necessary to compute
    dtype : dtype
        dtype for values
    dtype_max : dtype
        platform independent dtype
    fill_value : Any
        fill value used
    """
    mask = _maybe_get_mask(values, skipna, mask)

    if is_datetime64tz_dtype(values):
        # com.values_from_object returns M8[ns] dtype instead of tz-aware,
        #  so this case must be handled separately from the rest
        dtype = values.dtype
        values = getattr(values, "_values", values)
    else:
        values = com.values_from_object(values)
        dtype = values.dtype

    if is_datetime_or_timedelta_dtype(values) or is_datetime64tz_dtype(values):
        # changing timedelta64/datetime64 to int64 needs to happen after
        #  finding `mask` above
        values = getattr(values, "asi8", values)
        values = values.view(np.int64)

    dtype_ok = _na_ok_dtype(dtype)

    # get our fill value (in case we need to provide an alternative
    # dtype for it)
    fill_value = _get_fill_value(dtype, fill_value=fill_value,
                                 fill_value_typ=fill_value_typ)

    copy = (mask is not None) and (fill_value is not None)

    if skipna and copy:
        values = values.copy()
        if dtype_ok:
            np.putmask(values, mask, fill_value)

        # promote if needed
        else:
            values, changed = maybe_upcast_putmask(values, mask, fill_value)

    # return a platform independent precision dtype
    dtype_max = dtype
    if is_integer_dtype(dtype) or is_bool_dtype(dtype):
        dtype_max = np.int64
    elif is_float_dtype(dtype):
        dtype_max = np.float64

    return values, mask, dtype, dtype_max, fill_value
Beispiel #55
0
    def __floordiv__(self, other):
        if isinstance(other, (ABCSeries, ABCDataFrame, ABCIndexClass)):
            return NotImplemented

        other = lib.item_from_zerodim(other)
        if is_scalar(other):
            if isinstance(other, (timedelta, np.timedelta64, Tick)):
                other = Timedelta(other)
                if other is NaT:
                    # treat this specifically as timedelta-NaT
                    result = np.empty(self.shape, dtype=np.float64)
                    result.fill(np.nan)
                    return result

                # dispatch to Timedelta implementation
                result = other.__rfloordiv__(self._data)
                return result

            # at this point we should only have numeric scalars; anything
            #  else will raise
            result = self.asi8 // other
            result[self._isnan] = iNaT
            freq = None
            if self.freq is not None:
                # Note: freq gets division, not floor-division
                freq = self.freq / other
            return type(self)(result.view('m8[ns]'), freq=freq)

        if not hasattr(other, "dtype"):
            # list, tuple
            other = np.array(other)
        if len(other) != len(self):
            raise ValueError("Cannot divide with unequal lengths")

        elif is_timedelta64_dtype(other):
            other = type(self)(other)

            # numpy timedelta64 does not natively support floordiv, so operate
            #  on the i8 values
            result = self.asi8 // other.asi8
            mask = self._isnan | other._isnan
            if mask.any():
                result = result.astype(np.int64)
                result[mask] = np.nan
            return result

        elif is_object_dtype(other):
            result = [self[n] // other[n] for n in range(len(self))]
            result = np.array(result)
            if lib.infer_dtype(result) == 'timedelta':
                result, _ = sequence_to_td64ns(result)
                return type(self)(result)
            return result

        elif is_integer_dtype(other) or is_float_dtype(other):
            result = self._data // other
            return type(self)(result)

        else:
            dtype = getattr(other, "dtype", type(other).__name__)
            raise TypeError("Cannot divide {typ} by {cls}"
                            .format(typ=dtype, cls=type(self).__name__))
Beispiel #56
0
    def _simple_new(cls,
                    left,
                    right,
                    closed=None,
                    copy=False,
                    dtype=None,
                    verify_integrity=True):
        result = IntervalMixin.__new__(cls)

        closed = closed or "right"
        left = ensure_index(left, copy=copy)
        right = ensure_index(right, copy=copy)

        if dtype is not None:
            # GH 19262: dtype must be an IntervalDtype to override inferred
            dtype = pandas_dtype(dtype)
            if not is_interval_dtype(dtype):
                msg = f"dtype must be an IntervalDtype, got {dtype}"
                raise TypeError(msg)
            elif dtype.subtype is not None:
                left = left.astype(dtype.subtype)
                right = right.astype(dtype.subtype)

        # coerce dtypes to match if needed
        if is_float_dtype(left) and is_integer_dtype(right):
            right = right.astype(left.dtype)
        elif is_float_dtype(right) and is_integer_dtype(left):
            left = left.astype(right.dtype)

        if type(left) != type(right):
            msg = (f"must not have differing left [{type(left).__name__}] and "
                   f"right [{type(right).__name__}] types")
            raise ValueError(msg)
        elif is_categorical_dtype(left.dtype) or is_string_dtype(left.dtype):
            # GH 19016
            msg = ("category, object, and string subtypes are not supported "
                   "for IntervalArray")
            raise TypeError(msg)
        elif isinstance(left, ABCPeriodIndex):
            msg = "Period dtypes are not supported, use a PeriodIndex instead"
            raise ValueError(msg)
        elif isinstance(left,
                        ABCDatetimeIndex) and str(left.tz) != str(right.tz):
            msg = ("left and right must have the same time zone, got "
                   f"'{left.tz}' and '{right.tz}'")
            raise ValueError(msg)

        # For dt64/td64 we want DatetimeArray/TimedeltaArray instead of ndarray
        left = ensure_wrapped_if_datetimelike(left)
        left = extract_array(left, extract_numpy=True)
        right = ensure_wrapped_if_datetimelike(right)
        right = extract_array(right, extract_numpy=True)

        lbase = getattr(left, "_ndarray", left).base
        rbase = getattr(right, "_ndarray", right).base
        if lbase is not None and lbase is rbase:
            # If these share area_data, then setitem could corrupt our IA
            right = right.copy()

        result._left = left
        result._right = right
        result._closed = closed
        if verify_integrity:
            result._validate()
        return result
Beispiel #57
0
    def _arith_method(self, other, op):
        op_name = op.__name__
        omask = None

        if getattr(other, "ndim", 0) > 1:
            raise NotImplementedError(
                "can only perform ops with 1-d structures")

        if isinstance(other, IntegerArray):
            other, omask = other._data, other._mask

        elif is_list_like(other):
            other = np.asarray(other)
            if other.ndim > 1:
                raise NotImplementedError(
                    "can only perform ops with 1-d structures")
            if len(self) != len(other):
                raise ValueError("Lengths must match")
            if not (is_float_dtype(other) or is_integer_dtype(other)):
                raise TypeError("can only perform ops with numeric values")

        elif isinstance(other, (timedelta, np.timedelta64)):
            other = Timedelta(other)

        else:
            if not (is_float(other) or is_integer(other)
                    or other is libmissing.NA):
                raise TypeError("can only perform ops with numeric values")

        if omask is None:
            mask = self._mask.copy()
            if other is libmissing.NA:
                mask |= True
        else:
            mask = self._mask | omask

        if op_name == "pow":
            # 1 ** x is 1.
            mask = np.where((self._data == 1) & ~self._mask, False, mask)
            # x ** 0 is 1.
            if omask is not None:
                mask = np.where((other == 0) & ~omask, False, mask)
            elif other is not libmissing.NA:
                mask = np.where(other == 0, False, mask)

        elif op_name == "rpow":
            # 1 ** x is 1.
            if omask is not None:
                mask = np.where((other == 1) & ~omask, False, mask)
            elif other is not libmissing.NA:
                mask = np.where(other == 1, False, mask)
            # x ** 0 is 1.
            mask = np.where((self._data == 0) & ~self._mask, False, mask)

        if other is libmissing.NA:
            result = np.ones_like(self._data)
        else:
            with np.errstate(all="ignore"):
                result = op(self._data, other)

        # divmod returns a tuple
        if op_name == "divmod":
            div, mod = result
            return (
                self._maybe_mask_result(div, mask, other, "floordiv"),
                self._maybe_mask_result(mod, mask, other, "mod"),
            )

        return self._maybe_mask_result(result, mask, other, op_name)
Beispiel #58
0
def coerce_to_array(values,
                    dtype=None,
                    mask=None,
                    copy: bool = False) -> tuple[np.ndarray, np.ndarray]:
    """
    Coerce the input values array to numpy arrays with a mask.

    Parameters
    ----------
    values : 1D list-like
    dtype : float dtype
    mask : bool 1D array, optional
    copy : bool, default False
        if True, copy the input

    Returns
    -------
    tuple of (values, mask)
    """
    # if values is floating numpy array, preserve its dtype
    if dtype is None and hasattr(values, "dtype"):
        if is_float_dtype(values.dtype):
            dtype = values.dtype

    if dtype is not None:
        if isinstance(dtype, str) and dtype.startswith("Float"):
            # Avoid DeprecationWarning from NumPy about np.dtype("Float64")
            # https://github.com/numpy/numpy/pull/7476
            dtype = dtype.lower()

        if not issubclass(type(dtype), FloatingDtype):
            try:
                dtype = FLOAT_STR_TO_DTYPE[str(np.dtype(dtype))]
            except KeyError as err:
                raise ValueError(f"invalid dtype specified {dtype}") from err

    if isinstance(values, FloatingArray):
        values, mask = values._data, values._mask
        if dtype is not None:
            values = values.astype(dtype.numpy_dtype, copy=False)

        if copy:
            values = values.copy()
            mask = mask.copy()
        return values, mask

    values = np.array(values, copy=copy)
    if is_object_dtype(values):
        inferred_type = lib.infer_dtype(values, skipna=True)
        if inferred_type == "empty":
            pass
        elif inferred_type not in [
                "floating",
                "integer",
                "mixed-integer",
                "integer-na",
                "mixed-integer-float",
        ]:
            raise TypeError(
                f"{values.dtype} cannot be converted to a FloatingDtype")

    elif is_bool_dtype(values) and is_float_dtype(dtype):
        values = np.array(values, dtype=float, copy=copy)

    elif not (is_integer_dtype(values) or is_float_dtype(values)):
        raise TypeError(
            f"{values.dtype} cannot be converted to a FloatingDtype")

    if values.ndim != 1:
        raise TypeError("values must be a 1D list-like")

    if mask is None:
        mask = libmissing.is_numeric_na(values)

    else:
        assert len(mask) == len(values)

    if not mask.ndim == 1:
        raise TypeError("mask must be a 1D list-like")

    # infer dtype if needed
    if dtype is None:
        dtype = np.dtype("float64")
    else:
        dtype = dtype.type

    # if we are float, let's make sure that we can
    # safely cast

    # we copy as need to coerce here
    # TODO should this be a safe cast?
    if mask.any():
        values = values.copy()
        values[mask] = np.nan
    values = values.astype(dtype, copy=False)  # , casting="safe")

    return values, mask
Beispiel #59
0
def period_array(data, freq=None, copy=False):
    # type: (Sequence[Optional[Period]], Optional[Tick]) -> PeriodArray
    """
    Construct a new PeriodArray from a sequence of Period scalars.

    Parameters
    ----------
    data : Sequence of Period objects
        A sequence of Period objects. These are required to all have
        the same ``freq.`` Missing values can be indicated by ``None``
        or ``pandas.NaT``.
    freq : str, Tick, or Offset
        The frequency of every element of the array. This can be specified
        to avoid inferring the `freq` from `data`.
    copy : bool, default False
        Whether to ensure a copy of the data is made.

    Returns
    -------
    PeriodArray

    See Also
    --------
    PeriodArray
    pandas.PeriodIndex

    Examples
    --------
    >>> period_array([pd.Period('2017', freq='A'),
    ...               pd.Period('2018', freq='A')])
    <PeriodArray>
    ['2017', '2018']
    Length: 2, dtype: period[A-DEC]

    >>> period_array([pd.Period('2017', freq='A'),
    ...               pd.Period('2018', freq='A'),
    ...               pd.NaT])
    <PeriodArray>
    ['2017', '2018', 'NaT']
    Length: 3, dtype: period[A-DEC]

    Integers that look like years are handled

    >>> period_array([2000, 2001, 2002], freq='D')
    ['2000-01-01', '2001-01-01', '2002-01-01']
    Length: 3, dtype: period[D]

    Datetime-like strings may also be passed

    >>> period_array(['2000-Q1', '2000-Q2', '2000-Q3', '2000-Q4'], freq='Q')
    <PeriodArray>
    ['2000Q1', '2000Q2', '2000Q3', '2000Q4']
    Length: 4, dtype: period[Q-DEC]
    """
    if is_datetime64_dtype(data):
        return PeriodArray._from_datetime64(data, freq)
    if isinstance(data, (ABCPeriodIndex, ABCSeries, PeriodArray)):
        return PeriodArray(data, freq)

    # other iterable of some kind
    if not isinstance(data, (np.ndarray, list, tuple)):
        data = list(data)

    data = np.asarray(data)

    if freq:
        dtype = PeriodDtype(freq)
    else:
        dtype = None

    if is_float_dtype(data) and len(data) > 0:
        raise TypeError("PeriodIndex does not allow "
                        "floating point in construction")

    data = ensure_object(data)

    return PeriodArray._from_sequence(data, dtype=dtype)
Beispiel #60
0
def nanskew(
    values: np.ndarray,
    axis: Optional[int] = None,
    skipna: bool = True,
    mask: Optional[np.ndarray] = None,
) -> float:
    """
    Compute the sample skewness.

    The statistic computed here is the adjusted Fisher-Pearson standardized
    moment coefficient G1. The algorithm computes this coefficient directly
    from the second and third central moment.

    Parameters
    ----------
    values : ndarray
    axis: int, optional
    skipna : bool, default True
    mask : ndarray[bool], optional
        nan-mask if known

    Returns
    -------
    result : float64
        Unless input is a float array, in which case use the same
        precision as the input array.

    Examples
    --------
    >>> import pandas.core.nanops as nanops
    >>> s = pd.Series([1, np.nan, 1, 2])
    >>> nanops.nanskew(s)
    1.7320508075688787
    """
    values = extract_array(values, extract_numpy=True)
    mask = _maybe_get_mask(values, skipna, mask)
    if not is_float_dtype(values.dtype):
        values = values.astype("f8")
        count = _get_counts(values.shape, mask, axis)
    else:
        count = _get_counts(values.shape, mask, axis, dtype=values.dtype)

    if skipna and mask is not None:
        values = values.copy()
        np.putmask(values, mask, 0)

    mean = values.sum(axis, dtype=np.float64) / count
    if axis is not None:
        mean = np.expand_dims(mean, axis)

    adjusted = values - mean
    if skipna and mask is not None:
        np.putmask(adjusted, mask, 0)
    adjusted2 = adjusted**2
    adjusted3 = adjusted2 * adjusted
    m2 = adjusted2.sum(axis, dtype=np.float64)
    m3 = adjusted3.sum(axis, dtype=np.float64)

    # floating point error
    #
    # #18044 in _libs/windows.pyx calc_skew follow this behavior
    # to fix the fperr to treat m2 <1e-14 as zero
    m2 = _zero_out_fperr(m2)
    m3 = _zero_out_fperr(m3)

    with np.errstate(invalid="ignore", divide="ignore"):
        result = (count * (count - 1)**0.5 / (count - 2)) * (m3 / m2**1.5)

    dtype = values.dtype
    if is_float_dtype(dtype):
        result = result.astype(dtype)

    if isinstance(result, np.ndarray):
        result = np.where(m2 == 0, 0, result)
        result[count < 3] = np.nan
        return result
    else:
        result = 0 if m2 == 0 else result
        if count < 3:
            return np.nan
        return result