Ejemplo n.º 1
0
def _try_cast(arr, dtype: Optional[DtypeObj], copy: bool,
              raise_cast_failure: bool):
    """
    Convert input to numpy ndarray and optionally cast to a given dtype.

    Parameters
    ----------
    arr : ndarray, list, tuple, iterator (catchall)
        Excludes: ExtensionArray, Series, Index.
    dtype : np.dtype, ExtensionDtype or None
    copy : bool
        If False, don't copy the data if not needed.
    raise_cast_failure : bool
        If True, and if a dtype is specified, raise errors during casting.
        Otherwise an object array is returned.
    """
    # perf shortcut as this is the most common case
    if isinstance(arr, np.ndarray):
        if maybe_castable(arr) and not copy and dtype is None:
            return arr

    if isinstance(dtype, ExtensionDtype) and (dtype.kind != "M"
                                              or is_sparse(dtype)):
        # create an extension array from its dtype
        # DatetimeTZ case needs to go through maybe_cast_to_datetime but
        # SparseDtype does not
        array_type = dtype.construct_array_type()._from_sequence
        subarr = array_type(arr, dtype=dtype, copy=copy)
        return subarr

    if is_object_dtype(dtype) and not isinstance(arr, np.ndarray):
        subarr = construct_1d_object_array_from_listlike(arr)
        return subarr

    try:
        # GH#15832: Check if we are requesting a numeric dtype and
        # that we can convert the data to the requested dtype.
        if is_integer_dtype(dtype):
            # this will raise if we have e.g. floats
            maybe_cast_to_integer_array(arr, dtype)
            subarr = arr
        else:
            subarr = maybe_cast_to_datetime(arr, dtype)

        if not isinstance(subarr, (ABCExtensionArray, ABCIndex)):
            subarr = construct_1d_ndarray_preserving_na(subarr,
                                                        dtype,
                                                        copy=copy)
    except OutOfBoundsDatetime:
        # in case of out of bound datetime64 -> always raise
        raise
    except (ValueError, TypeError) as err:
        if dtype is not None and raise_cast_failure:
            raise
        elif "Cannot cast" in str(err):
            # via _disallow_mismatched_datetimelike
            raise
        else:
            subarr = np.array(arr, dtype=object, copy=copy)
    return subarr
Ejemplo n.º 2
0
def _try_cast(
    arr, dtype: Optional[DtypeObj], copy: bool, raise_cast_failure: bool,
):
    """
    Convert input to numpy ndarray and optionally cast to a given dtype.

    Parameters
    ----------
    arr : ndarray, list, tuple, iterator (catchall)
        Excludes: ExtensionArray, Series, Index.
    dtype : np.dtype, ExtensionDtype or None
    copy : bool
        If False, don't copy the data if not needed.
    raise_cast_failure : bool
        If True, and if a dtype is specified, raise errors during casting.
        Otherwise an object array is returned.
    """
    # perf shortcut as this is the most common case
    if isinstance(arr, np.ndarray):
        if maybe_castable(arr) and not copy and dtype is None:
            return arr

    try:
        # GH#15832: Check if we are requesting a numeric dype and
        # that we can convert the data to the requested dtype.
        if is_integer_dtype(dtype):
            subarr = maybe_cast_to_integer_array(arr, dtype)

        subarr = maybe_cast_to_datetime(arr, dtype)
        # Take care in creating object arrays (but iterators are not
        # supported):
        if is_object_dtype(dtype) and (
            is_list_like(subarr)
            and not (is_iterator(subarr) or isinstance(subarr, np.ndarray))
        ):
            subarr = construct_1d_object_array_from_listlike(subarr)
        elif not is_extension_array_dtype(subarr):
            subarr = construct_1d_ndarray_preserving_na(subarr, dtype, copy=copy)
    except OutOfBoundsDatetime:
        # in case of out of bound datetime64 -> always raise
        raise
    except (ValueError, TypeError):
        if is_categorical_dtype(dtype):
            # We *do* allow casting to categorical, since we know
            # that Categorical is the only array type for 'category'.
            dtype = cast(CategoricalDtype, dtype)
            subarr = dtype.construct_array_type()(
                arr, dtype.categories, ordered=dtype.ordered
            )
        elif is_extension_array_dtype(dtype):
            # create an extension array from its dtype
            dtype = cast(ExtensionDtype, dtype)
            array_type = dtype.construct_array_type()._from_sequence
            subarr = array_type(arr, dtype=dtype, copy=copy)
        elif dtype is not None and raise_cast_failure:
            raise
        else:
            subarr = np.array(arr, dtype=object, copy=copy)
    return subarr
Ejemplo n.º 3
0
def _try_cast(arr, take_fast_path, dtype, copy, raise_cast_failure):

    # perf shortcut as this is the most common case
    if take_fast_path:
        if maybe_castable(arr) and not copy and dtype is None:
            return arr

    try:
        # GH#15832: Check if we are requesting a numeric dype and
        # that we can convert the data to the requested dtype.
        if is_integer_dtype(dtype):
            subarr = maybe_cast_to_integer_array(arr, dtype)

        subarr = maybe_cast_to_datetime(arr, dtype)
        # Take care in creating object arrays (but iterators are not
        # supported):
        if is_object_dtype(dtype) and (
                is_list_like(subarr) and
                not (is_iterator(subarr) or isinstance(subarr, np.ndarray))):
            subarr = construct_1d_object_array_from_listlike(subarr)
        elif not is_extension_type(subarr):
            subarr = construct_1d_ndarray_preserving_na(subarr,
                                                        dtype,
                                                        copy=copy)
    except OutOfBoundsDatetime:
        # in case of out of bound datetime64 -> always raise
        raise
    except (ValueError, TypeError):
        if is_categorical_dtype(dtype):
            # We *do* allow casting to categorical, since we know
            # that Categorical is the only array type for 'category'.
            subarr = Categorical(arr, dtype.categories, ordered=dtype.ordered)
        elif is_extension_array_dtype(dtype):
            # create an extension array from its dtype
            array_type = dtype.construct_array_type()._from_sequence
            subarr = array_type(arr, dtype=dtype, copy=copy)
        elif dtype is not None and raise_cast_failure:
            raise
        else:
            subarr = np.array(arr, dtype=object, copy=copy)
    return subarr
Ejemplo n.º 4
0
def _try_cast(arr, take_fast_path, dtype, copy, raise_cast_failure):

    # perf shortcut as this is the most common case
    if take_fast_path:
        if maybe_castable(arr) and not copy and dtype is None:
            return arr

    try:
        # GH#15832: Check if we are requesting a numeric dype and
        # that we can convert the data to the requested dtype.
        if is_integer_dtype(dtype):
            subarr = maybe_cast_to_integer_array(arr, dtype)

        subarr = maybe_cast_to_datetime(arr, dtype)
        # Take care in creating object arrays (but iterators are not
        # supported):
        if is_object_dtype(dtype) and (is_list_like(subarr) and
                                       not (is_iterator(subarr) or
                                       isinstance(subarr, np.ndarray))):
            subarr = construct_1d_object_array_from_listlike(subarr)
        elif not is_extension_type(subarr):
            subarr = construct_1d_ndarray_preserving_na(subarr, dtype,
                                                        copy=copy)
    except (ValueError, TypeError):
        if is_categorical_dtype(dtype):
            # We *do* allow casting to categorical, since we know
            # that Categorical is the only array type for 'category'.
            subarr = Categorical(arr, dtype.categories,
                                 ordered=dtype.ordered)
        elif is_extension_array_dtype(dtype):
            # create an extension array from its dtype
            array_type = dtype.construct_array_type()._from_sequence
            subarr = array_type(arr, dtype=dtype, copy=copy)
        elif dtype is not None and raise_cast_failure:
            raise
        else:
            subarr = np.array(arr, dtype=object, copy=copy)
    return subarr
Ejemplo n.º 5
0
def _try_cast(
    arr: list | np.ndarray,
    dtype: DtypeObj | None,
    copy: bool,
    raise_cast_failure: bool,
) -> ArrayLike:
    """
    Convert input to numpy ndarray and optionally cast to a given dtype.

    Parameters
    ----------
    arr : ndarray or list
        Excludes: ExtensionArray, Series, Index.
    dtype : np.dtype, ExtensionDtype or None
    copy : bool
        If False, don't copy the data if not needed.
    raise_cast_failure : bool
        If True, and if a dtype is specified, raise errors during casting.
        Otherwise an object array is returned.

    Returns
    -------
    np.ndarray or ExtensionArray
    """
    # perf shortcut as this is the most common case
    if (isinstance(arr, np.ndarray) and maybe_castable(arr.dtype) and not copy
            and dtype is None):
        return arr

    if isinstance(dtype,
                  ExtensionDtype) and not isinstance(dtype, DatetimeTZDtype):
        # create an extension array from its dtype
        # DatetimeTZ case needs to go through maybe_cast_to_datetime but
        # SparseDtype does not
        array_type = dtype.construct_array_type()._from_sequence
        subarr = array_type(arr, dtype=dtype, copy=copy)
        return subarr

    if is_object_dtype(dtype) and not isinstance(arr, np.ndarray):
        subarr = construct_1d_object_array_from_listlike(arr)
        return subarr

    try:
        # GH#15832: Check if we are requesting a numeric dtype and
        # that we can convert the data to the requested dtype.
        if is_integer_dtype(dtype):
            # this will raise if we have e.g. floats

            # error: Argument 2 to "maybe_cast_to_integer_array" has incompatible type
            # "Union[dtype, ExtensionDtype, None]"; expected "Union[ExtensionDtype, str,
            # dtype, Type[str], Type[float], Type[int], Type[complex], Type[bool],
            # Type[object]]"
            maybe_cast_to_integer_array(arr, dtype)  # type: ignore[arg-type]
            subarr = arr
        else:
            subarr = maybe_cast_to_datetime(arr, dtype)
            if dtype is not None and dtype.kind == "M":
                return subarr

        if not isinstance(subarr, ABCExtensionArray):
            subarr = construct_1d_ndarray_preserving_na(subarr,
                                                        dtype,
                                                        copy=copy)
    except OutOfBoundsDatetime:
        # in case of out of bound datetime64 -> always raise
        raise
    except (ValueError, TypeError) as err:
        if dtype is not None and raise_cast_failure:
            raise
        elif "Cannot cast" in str(err):
            # via _disallow_mismatched_datetimelike
            raise
        else:
            subarr = np.array(arr, dtype=object, copy=copy)
    return subarr
Ejemplo n.º 6
0
def _try_cast(
    arr: list | np.ndarray,
    dtype: DtypeObj | None,
    copy: bool,
    raise_cast_failure: bool,
) -> ArrayLike:
    """
    Convert input to numpy ndarray and optionally cast to a given dtype.

    Parameters
    ----------
    arr : ndarray or list
        Excludes: ExtensionArray, Series, Index.
    dtype : np.dtype, ExtensionDtype or None
    copy : bool
        If False, don't copy the data if not needed.
    raise_cast_failure : bool
        If True, and if a dtype is specified, raise errors during casting.
        Otherwise an object array is returned.

    Returns
    -------
    np.ndarray or ExtensionArray
    """
    is_ndarray = isinstance(arr, np.ndarray)

    if dtype is None:
        # perf shortcut as this is the most common case
        if is_ndarray:
            arr = cast(np.ndarray, arr)
            if arr.dtype != object:
                return sanitize_to_nanoseconds(arr, copy=copy)

            out = maybe_infer_to_datetimelike(arr)
            if out is arr and copy:
                out = out.copy()
            return out

        else:
            # i.e. list
            varr = np.array(arr, copy=False)
            # filter out cases that we _dont_ want to go through
            #  maybe_infer_to_datetimelike
            if varr.dtype != object or varr.size == 0:
                return varr
            return maybe_infer_to_datetimelike(varr)

    elif isinstance(dtype, ExtensionDtype):
        # create an extension array from its dtype
        if isinstance(dtype, DatetimeTZDtype):
            # We can't go through _from_sequence because it handles dt64naive
            #  data differently; _from_sequence treats naive as wall times,
            #  while maybe_cast_to_datetime treats it as UTC
            #  see test_maybe_promote_any_numpy_dtype_with_datetimetz
            # TODO(2.0): with deprecations enforced, should be able to remove
            #  special case.
            return maybe_cast_to_datetime(arr, dtype)
            # TODO: copy?

        array_type = dtype.construct_array_type()._from_sequence
        subarr = array_type(arr, dtype=dtype, copy=copy)
        return subarr

    elif is_object_dtype(dtype):
        if not is_ndarray:
            subarr = construct_1d_object_array_from_listlike(arr)
            return subarr
        return ensure_wrapped_if_datetimelike(arr).astype(dtype, copy=copy)

    elif dtype.kind == "U":
        # TODO: test cases with arr.dtype.kind in ["m", "M"]
        return lib.ensure_string_array(arr, convert_na_value=False, copy=copy)

    elif dtype.kind in ["m", "M"]:
        return maybe_cast_to_datetime(arr, dtype)

    try:
        # GH#15832: Check if we are requesting a numeric dtype and
        # that we can convert the data to the requested dtype.
        if is_integer_dtype(dtype):
            # this will raise if we have e.g. floats

            subarr = maybe_cast_to_integer_array(arr, dtype)
        else:
            # 4 tests fail if we move this to a try/except/else; see
            #  test_constructor_compound_dtypes, test_constructor_cast_failure
            #  test_constructor_dict_cast2, test_loc_setitem_dtype
            subarr = np.array(arr, dtype=dtype, copy=copy)

    except (ValueError, TypeError):
        if raise_cast_failure:
            raise
        else:
            # we only get here with raise_cast_failure False, which means
            #  called via the DataFrame constructor
            # GH#24435
            warnings.warn(
                f"Could not cast to {dtype}, falling back to object. This "
                "behavior is deprecated. In a future version, when a dtype is "
                "passed to 'DataFrame', either all columns will be cast to that "
                "dtype, or a TypeError will be raised.",
                FutureWarning,
                stacklevel=find_stack_level(),
            )
            subarr = np.array(arr, dtype=object, copy=copy)
    return subarr
Ejemplo n.º 7
0
def _try_cast(
    arr: list | np.ndarray,
    dtype: DtypeObj | None,
    copy: bool,
    raise_cast_failure: bool,
) -> ArrayLike:
    """
    Convert input to numpy ndarray and optionally cast to a given dtype.

    Parameters
    ----------
    arr : ndarray or list
        Excludes: ExtensionArray, Series, Index.
    dtype : np.dtype, ExtensionDtype or None
    copy : bool
        If False, don't copy the data if not needed.
    raise_cast_failure : bool
        If True, and if a dtype is specified, raise errors during casting.
        Otherwise an object array is returned.

    Returns
    -------
    np.ndarray or ExtensionArray
    """
    is_ndarray = isinstance(arr, np.ndarray)

    # perf shortcut as this is the most common case
    # Item "List[Any]" of "Union[List[Any], ndarray]" has no attribute "dtype"
    if (is_ndarray and arr.dtype != object  # type: ignore[union-attr]
            and not copy and dtype is None):
        # Argument 1 to "sanitize_to_nanoseconds" has incompatible type
        # "Union[List[Any], ndarray]"; expected "ndarray"
        return sanitize_to_nanoseconds(arr)  # type: ignore[arg-type]

    if isinstance(dtype, ExtensionDtype):
        # create an extension array from its dtype
        # DatetimeTZ case needs to go through maybe_cast_to_datetime but
        # SparseDtype does not
        if isinstance(dtype, DatetimeTZDtype):
            # We can't go through _from_sequence because it handles dt64naive
            #  data differently; _from_sequence treats naive as wall times,
            #  while maybe_cast_to_datetime treats it as UTC
            #  see test_maybe_promote_any_numpy_dtype_with_datetimetz

            # error: Incompatible return value type (got "Union[ExtensionArray,
            # ndarray, List[Any]]", expected "Union[ExtensionArray, ndarray]")
            return maybe_cast_to_datetime(arr,
                                          dtype)  # type: ignore[return-value]
            # TODO: copy?

        array_type = dtype.construct_array_type()._from_sequence
        subarr = array_type(arr, dtype=dtype, copy=copy)
        return subarr

    elif is_object_dtype(dtype):
        if not is_ndarray:
            subarr = construct_1d_object_array_from_listlike(arr)
            return subarr
        return ensure_wrapped_if_datetimelike(arr).astype(dtype, copy=copy)

    elif dtype is None and not is_ndarray:
        # filter out cases that we _dont_ want to go through maybe_cast_to_datetime
        varr = np.array(arr, copy=False)
        if varr.dtype != object or varr.size == 0:
            return varr
        # error: Incompatible return value type (got "Union[ExtensionArray,
        # ndarray, List[Any]]", expected "Union[ExtensionArray, ndarray]")
        return maybe_cast_to_datetime(varr, None)  # type: ignore[return-value]

    try:
        # GH#15832: Check if we are requesting a numeric dtype and
        # that we can convert the data to the requested dtype.
        if is_integer_dtype(dtype):
            # this will raise if we have e.g. floats

            dtype = cast(np.dtype, dtype)
            maybe_cast_to_integer_array(arr, dtype)
            subarr = arr
        else:
            subarr = maybe_cast_to_datetime(arr, dtype)
            if dtype is not None and dtype.kind == "M":
                return subarr

        if not isinstance(subarr, ABCExtensionArray):
            subarr = construct_1d_ndarray_preserving_na(subarr,
                                                        dtype,
                                                        copy=copy)
    except OutOfBoundsDatetime:
        # in case of out of bound datetime64 -> always raise
        raise
    except (ValueError, TypeError) as err:
        if dtype is not None and raise_cast_failure:
            raise
        elif "Cannot cast" in str(err):
            # via _disallow_mismatched_datetimelike
            raise
        else:
            subarr = np.array(arr, dtype=object, copy=copy)
    return subarr