Convert input to numpy ndarray and optionally cast to a given dtype. Parameters ---------- arr : ndarray or list Excludes: ExtensionArray, Series, Index. dtype : np.dtype copy : bool If False, don't copy the data if not needed. Returns ------- n
(
arr: list | np.ndarray,
dtype: np.dtype,
copy: bool,
)
| 789 | |
| 790 | |
| 791 | def _try_cast( |
| 792 | arr: list | np.ndarray, |
| 793 | dtype: np.dtype, |
| 794 | copy: bool, |
| 795 | ) -> ArrayLike: |
| 796 | """ |
| 797 | Convert input to numpy ndarray and optionally cast to a given dtype. |
| 798 | |
| 799 | Parameters |
| 800 | ---------- |
| 801 | arr : ndarray or list |
| 802 | Excludes: ExtensionArray, Series, Index. |
| 803 | dtype : np.dtype |
| 804 | copy : bool |
| 805 | If False, don't copy the data if not needed. |
| 806 | |
| 807 | Returns |
| 808 | ------- |
| 809 | np.ndarray or ExtensionArray |
| 810 | """ |
| 811 | is_ndarray = isinstance(arr, np.ndarray) |
| 812 | |
| 813 | if dtype == object: |
| 814 | if not is_ndarray: |
| 815 | subarr = construct_1d_object_array_from_listlike(arr) |
| 816 | return subarr |
| 817 | return ensure_wrapped_if_datetimelike(arr).astype(dtype, copy=copy) |
| 818 | |
| 819 | elif dtype.kind == "U": |
| 820 | # TODO: test cases with arr.dtype.kind in "mM" |
| 821 | if is_ndarray: |
| 822 | arr = cast(np.ndarray, arr) |
| 823 | shape = arr.shape |
| 824 | if arr.ndim > 1: |
| 825 | arr = arr.ravel() |
| 826 | else: |
| 827 | shape = (len(arr),) |
| 828 | return lib.ensure_string_array(arr, convert_na_value=False, copy=copy).reshape( |
| 829 | shape |
| 830 | ) |
| 831 | |
| 832 | elif dtype.kind in "mM": |
| 833 | if is_ndarray: |
| 834 | arr = cast(np.ndarray, arr) |
| 835 | if arr.ndim == 2 and arr.shape[1] == 1: |
| 836 | # GH#60081: DataFrame Constructor converts 1D data to array of |
| 837 | # shape (N, 1), but maybe_cast_to_datetime assumes 1D input |
| 838 | return maybe_cast_to_datetime(arr[:, 0], dtype).reshape(arr.shape) |
| 839 | return maybe_cast_to_datetime(arr, dtype) |
| 840 | |
| 841 | # GH#15832: Check if we are requesting a numeric dtype and |
| 842 | # that we can convert the data to the requested dtype. |
| 843 | elif dtype.kind in "iu": |
| 844 | # this will raise if we have e.g. floats |
| 845 | |
| 846 | subarr = maybe_cast_to_integer_array(arr, dtype) |
| 847 | elif not copy: |
| 848 | subarr = np.asarray(arr, dtype=dtype) |
no test coverage detected