Exemplo n.º 1
0
    def where(self, cond, other=None):
        values = self.view("i8")

        if is_scalar(other) and isna(other):
            other = NaT.value

        else:
            # Do type inference if necessary up front
            # e.g. we passed PeriodIndex.values and got an ndarray of Periods
            other = Index(other)

            if is_categorical_dtype(other):
                # e.g. we have a Categorical holding self.dtype
                if is_dtype_equal(other.categories.dtype, self.dtype):
                    other = other._internal_get_values()

            if not is_dtype_equal(self.dtype, other.dtype):
                raise TypeError(
                    f"Where requires matching dtype, not {other.dtype}")

            other = other.view("i8")

        result = np.where(cond, values, other).astype("i8")
        arr = type(self._data)._simple_new(result, dtype=self.dtype)
        return type(self)._simple_new(arr, name=self.name)
Exemplo n.º 2
0
    def where(self, cond, other=None):
        values = self.view("i8")

        if is_scalar(other) and isna(other):
            other = NaT.value

        else:
            # Do type inference if necessary up front
            # e.g. we passed PeriodIndex.values and got an ndarray of Periods
            other = Index(other)

            if is_categorical_dtype(other):
                # e.g. we have a Categorical holding self.dtype
                if needs_i8_conversion(other.categories):
                    other = other._internal_get_values()

            if not is_dtype_equal(self.dtype, other.dtype):
                raise TypeError(f"Where requires matching dtype, not {other.dtype}")

            other = other.view("i8")

        result = np.where(cond, values, other).astype("i8")
        return self._shallow_copy(result)
Exemplo n.º 3
0
def _convert_listlike_datetimes(
    arg,
    format,
    name=None,
    tz=None,
    unit=None,
    errors=None,
    infer_datetime_format=None,
    dayfirst=None,
    yearfirst=None,
    exact=None,
):
    """
    Helper function for to_datetime. Performs the conversions of 1D listlike
    of dates

    Parameters
    ----------
    arg : list, tuple, ndarray, Series, Index
        date to be parsed
    name : object
        None or string for the Index name
    tz : object
        None or 'utc'
    unit : string
        None or string of the frequency of the passed data
    errors : string
        error handing behaviors from to_datetime, 'raise', 'coerce', 'ignore'
    infer_datetime_format : boolean
        inferring format behavior from to_datetime
    dayfirst : boolean
        dayfirst parsing behavior from to_datetime
    yearfirst : boolean
        yearfirst parsing behavior from to_datetime
    exact : boolean
        exact format matching behavior from to_datetime

    Returns
    -------
    Index-like of parsed dates
    """

    if isinstance(arg, (list, tuple)):
        arg = np.array(arg, dtype="O")

    arg_dtype = getattr(arg, "dtype", None)
    # these are shortcutable
    if is_datetime64tz_dtype(arg_dtype):
        if not isinstance(arg, (DatetimeArray, DatetimeIndex)):
            return DatetimeIndex(arg, tz=tz, name=name)
        if tz == "utc":
            # error: Item "DatetimeIndex" of "Union[DatetimeArray, DatetimeIndex]" has
            # no attribute "tz_convert"
            arg = arg.tz_convert(None).tz_localize(tz)  # type: ignore
        return arg

    elif is_datetime64_ns_dtype(arg_dtype):
        if not isinstance(arg, (DatetimeArray, DatetimeIndex)):
            try:
                return DatetimeIndex(arg, tz=tz, name=name)
            except ValueError:
                pass
        elif tz:
            # DatetimeArray, DatetimeIndex
            # error: Item "DatetimeIndex" of "Union[DatetimeArray, DatetimeIndex]" has
            # no attribute "tz_localize"
            return arg.tz_localize(tz)  # type: ignore

        return arg

    elif unit is not None:
        if format is not None:
            raise ValueError("cannot specify both format and unit")
        arg = getattr(arg, "_values", arg)

        # GH 30050 pass an ndarray to tslib.array_with_unit_to_datetime
        # because it expects an ndarray argument
        if isinstance(arg, IntegerArray):
            result = arg.astype(f"datetime64[{unit}]")
            tz_parsed = None
        else:

            result, tz_parsed = tslib.array_with_unit_to_datetime(
                arg, unit, errors=errors)

        if errors == "ignore":

            result = Index(result, name=name)
        else:
            result = DatetimeIndex(result, name=name)
        # GH 23758: We may still need to localize the result with tz
        # GH 25546: Apply tz_parsed first (from arg), then tz (from caller)
        # result will be naive but in UTC
        try:
            result = result.tz_localize("UTC").tz_convert(tz_parsed)
        except AttributeError:
            # Regular Index from 'ignore' path
            return result
        if tz is not None:
            if result.tz is None:
                result = result.tz_localize(tz)
            else:
                result = result.tz_convert(tz)
        return result
    elif getattr(arg, "ndim", 1) > 1:
        raise TypeError(
            "arg must be a string, datetime, list, tuple, 1-d array, or Series"
        )

    # warn if passing timedelta64, raise for PeriodDtype
    # NB: this must come after unit transformation
    orig_arg = arg
    try:
        arg, _ = maybe_convert_dtype(arg, copy=False)
    except TypeError:
        if errors == "coerce":
            result = np.array(["NaT"], dtype="datetime64[ns]").repeat(len(arg))
            return DatetimeIndex(result, name=name)
        elif errors == "ignore":
            result = Index(arg, name=name)
            return result
        raise

    arg = ensure_object(arg)
    require_iso8601 = False

    if infer_datetime_format and format is None:
        format = _guess_datetime_format_for_array(arg, dayfirst=dayfirst)

    if format is not None:
        # There is a special fast-path for iso8601 formatted
        # datetime strings, so in those cases don't use the inferred
        # format because this path makes process slower in this
        # special case
        format_is_iso8601 = _format_is_iso(format)
        if format_is_iso8601:
            require_iso8601 = not infer_datetime_format
            format = None

    tz_parsed = None
    result = None

    if format is not None:
        try:
            # shortcut formatting here
            if format == "%Y%m%d":
                try:
                    # pass orig_arg as float-dtype may have been converted to
                    # datetime64[ns]
                    orig_arg = ensure_object(orig_arg)
                    result = _attempt_YYYYMMDD(orig_arg, errors=errors)
                except (ValueError, TypeError,
                        tslibs.OutOfBoundsDatetime) as err:
                    raise ValueError(
                        "cannot convert the input to '%Y%m%d' date format"
                    ) from err

            # fallback
            if result is None:
                try:
                    result, timezones = array_strptime(arg,
                                                       format,
                                                       exact=exact,
                                                       errors=errors)
                    if "%Z" in format or "%z" in format:
                        return _return_parsed_timezone_results(
                            result, timezones, tz, name)
                except tslibs.OutOfBoundsDatetime:
                    if errors == "raise":
                        raise
                    elif errors == "coerce":
                        result = np.empty(arg.shape, dtype="M8[ns]")
                        iresult = result.view("i8")
                        iresult.fill(tslibs.iNaT)
                    else:
                        result = arg
                except ValueError:
                    # if format was inferred, try falling back
                    # to array_to_datetime - terminate here
                    # for specified formats
                    if not infer_datetime_format:
                        if errors == "raise":
                            raise
                        elif errors == "coerce":
                            result = np.empty(arg.shape, dtype="M8[ns]")
                            iresult = result.view("i8")
                            iresult.fill(tslibs.iNaT)
                        else:
                            result = arg
        except ValueError as e:
            # Fallback to try to convert datetime objects if timezone-aware
            #  datetime objects are found without passing `utc=True`
            try:
                values, tz = conversion.datetime_to_datetime64(arg)
                dta = DatetimeArray(values, dtype=tz_to_dtype(tz))
                return DatetimeIndex._simple_new(dta, name=name)
            except (ValueError, TypeError):
                raise e

    if result is None:
        assert format is None or infer_datetime_format
        utc = tz == "utc"
        result, tz_parsed = objects_to_datetime64ns(
            arg,
            dayfirst=dayfirst,
            yearfirst=yearfirst,
            utc=utc,
            errors=errors,
            require_iso8601=require_iso8601,
            allow_object=True,
        )

    if tz_parsed is not None:
        # We can take a shortcut since the datetime64 numpy array
        # is in UTC
        dta = DatetimeArray(result, dtype=tz_to_dtype(tz_parsed))
        return DatetimeIndex._simple_new(dta, name=name)

    utc = tz == "utc"
    return _box_as_indexlike(result, utc=utc, name=name)