pandas.api.extensions.ExtensionArray.astype — pandas 2.2.3 documentation (original) (raw)

ExtensionArray.astype(dtype, copy=True)[source]#

Cast to a NumPy array or ExtensionArray with ‘dtype’.

Parameters:

dtypestr or dtype

Typecode or data-type to which the array is cast.

copybool, default True

Whether to copy the data, even if not necessary. If False, a copy is made only if the old dtype does not match the new dtype.

Returns:

np.ndarray or pandas.api.extensions.ExtensionArray

An ExtensionArray if dtype is ExtensionDtype, otherwise a Numpy ndarray with dtype for its dtype.

Examples

arr = pd.array([1, 2, 3]) arr [1, 2, 3] Length: 3, dtype: Int64

Casting to another ExtensionDtype returns an ExtensionArray:

arr1 = arr.astype('Float64') arr1 [1.0, 2.0, 3.0] Length: 3, dtype: Float64 arr1.dtype Float64Dtype()

Otherwise, we will get a Numpy ndarray:

arr2 = arr.astype('float64') arr2 array([1., 2., 3.]) arr2.dtype dtype('float64')