示例#1
0
def _isnull_ndarraylike(obj):

    values = getattr(obj, 'values', obj)
    dtype = values.dtype

    if is_string_dtype(dtype):
        if is_categorical_dtype(values):
            from pandas import Categorical
            if not isinstance(values, Categorical):
                values = values.values
            result = values.isnull()
        else:

            # Working around NumPy ticket 1542
            shape = values.shape

            if is_string_like_dtype(dtype):
                result = np.zeros(values.shape, dtype=bool)
            else:
                result = np.empty(shape, dtype=bool)
                vec = lib.isnullobj(values.ravel())
                result[...] = vec.reshape(shape)

    elif needs_i8_conversion(obj):
        # this is the NaT pattern
        result = values.view('i8') == iNaT
    else:
        result = np.isnan(values)

    # box
    if isinstance(obj, ABCSeries):
        from pandas import Series
        result = Series(result, index=obj.index, name=obj.name, copy=False)

    return result
示例#2
0
def _isnull_ndarraylike(obj):
    from pandas import Series
    values = np.asarray(obj)

    if values.dtype.kind in ('O', 'S', 'U'):
        # Working around NumPy ticket 1542
        shape = values.shape

        if values.dtype.kind in ('S', 'U'):
            result = np.zeros(values.shape, dtype=bool)
        else:
            result = np.empty(shape, dtype=bool)
            vec = lib.isnullobj(values.ravel())
            result[:] = vec.reshape(shape)

        if isinstance(obj, Series):
            result = Series(result, index=obj.index, copy=False)
    elif values.dtype == np.dtype('M8[ns]'):
        # this is the NaT pattern
        result = values.view('i8') == lib.iNaT
    elif issubclass(values.dtype.type, np.timedelta64):
        result = -np.isfinite(values.view('i8'))
    else:
        result = -np.isfinite(obj)
    return result
示例#3
0
def _isnull_ndarraylike(obj):
    from pandas import Series
    values = np.asarray(obj)

    if values.dtype.kind in ('O', 'S', 'U'):
        # Working around NumPy ticket 1542
        shape = values.shape

        if values.dtype.kind in ('S', 'U'):
            result = np.zeros(values.shape, dtype=bool)
        else:
            result = np.empty(shape, dtype=bool)
            vec = lib.isnullobj(values.ravel())
            result[:] = vec.reshape(shape)

        if isinstance(obj, Series):
            result = Series(result, index=obj.index, copy=False)
    elif values.dtype == np.dtype('M8[ns]'):
        # this is the NaT pattern
        result = values.view('i8') == lib.iNaT
    elif issubclass(values.dtype.type, np.timedelta64):
        result = -np.isfinite(values.view('i8'))
    else:
        result = -np.isfinite(obj)
    return result
示例#4
0
def _isnull_ndarraylike(obj):

    values = getattr(obj, 'values', obj)
    dtype = values.dtype

    if is_string_dtype(dtype):
        if is_categorical_dtype(values):
            from pandas import Categorical
            if not isinstance(values, Categorical):
                values = values.values
            result = values.isnull()
        else:

            # Working around NumPy ticket 1542
            shape = values.shape

            if is_string_like_dtype(dtype):
                result = np.zeros(values.shape, dtype=bool)
            else:
                result = np.empty(shape, dtype=bool)
                vec = lib.isnullobj(values.ravel())
                result[...] = vec.reshape(shape)

    elif needs_i8_conversion(obj):
        # this is the NaT pattern
        result = values.view('i8') == iNaT
    else:
        result = np.isnan(values)

    # box
    if isinstance(obj, ABCSeries):
        from pandas import Series
        result = Series(result, index=obj.index, name=obj.name, copy=False)

    return result
示例#5
0
文件: common.py 项目: zkluo1/pandas
def _isnull_ndarraylike(obj):
    from pandas import Series

    values = np.asarray(obj)

    if values.dtype.kind in ("O", "S"):
        # Working around NumPy ticket 1542
        shape = values.shape
        result = np.empty(shape, dtype=bool)
        vec = lib.isnullobj(values.ravel())
        result[:] = vec.reshape(shape)

        if isinstance(obj, Series):
            result = Series(result, index=obj.index, copy=False)
    elif values.dtype == np.dtype("M8[ns]"):
        # this is the NaT pattern
        result = values.view("i8") == lib.iNaT
    else:
        result = -np.isfinite(obj)
    return result
示例#6
0
文件: common.py 项目: afonit/pandas
def isnull(obj):
    '''
    Replacement for numpy.isnan / -numpy.isfinite which is suitable
    for use on object arrays.

    Parameters
    ----------
    arr: ndarray or object value

    Returns
    -------
    boolean ndarray or boolean
    '''
    if lib.isscalar(obj):
        return lib.checknull(obj)

    from pandas.core.generic import PandasObject
    from pandas import Series
    if isinstance(obj, np.ndarray):
        if obj.dtype.kind in ('O', 'S'):
            # Working around NumPy ticket 1542
            shape = obj.shape
            result = np.empty(shape, dtype=bool)
            vec = lib.isnullobj(obj.ravel())
            result[:] = vec.reshape(shape)

            if isinstance(obj, Series):
                result = Series(result, index=obj.index, copy=False)
        elif obj.dtype == np.dtype('M8[ns]'):
            # this is the NaT pattern
            result = np.array(obj).view('i8') == lib.iNaT
        else:
            result = -np.isfinite(obj)
        return result
    elif isinstance(obj, PandasObject):
        # TODO: optimize for DataFrame, etc.
        return obj.apply(isnull)
    else:
        return obj is None
示例#7
0
def isnull(obj):
    '''
    Replacement for numpy.isnan / -numpy.isfinite which is suitable
    for use on object arrays.

    Parameters
    ----------
    arr: ndarray or object value

    Returns
    -------
    boolean ndarray or boolean
    '''
    if lib.isscalar(obj):
        return lib.checknull(obj)

    from pandas.core.generic import PandasObject
    from pandas import Series
    if isinstance(obj, np.ndarray):
        if obj.dtype.kind in ('O', 'S'):
            # Working around NumPy ticket 1542
            shape = obj.shape
            result = np.empty(shape, dtype=bool)
            vec = lib.isnullobj(obj.ravel())
            result[:] = vec.reshape(shape)

            if isinstance(obj, Series):
                result = Series(result, index=obj.index, copy=False)
        elif obj.dtype == np.dtype('M8[ns]'):
            # this is the NaT pattern
            result = np.array(obj).view('i8') == lib.iNaT
        else:
            result = -np.isfinite(obj)
        return result
    elif isinstance(obj, PandasObject):
        # TODO: optimize for DataFrame, etc.
        return obj.apply(isnull)
    else:
        return obj is None