pandas.api.extensions.ExtensionArray.astype#

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.

See also

Series.astype: Cast a Series to a different dtype.
DataFrame.astype: Cast a DataFrame to a different dtype.
api.extensions.ExtensionArray: Base class for ExtensionArray objects.
core.arrays.DatetimeArray._from_sequence: Create a DatetimeArray from a sequence.
core.arrays.TimedeltaArray._from_sequence: Create a TimedeltaArray from a sequence.

Examples

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

Casting to another ExtensionDtype returns an ExtensionArray:

>>> arr1 = arr.astype("Float64")
>>> arr1
<FloatingArray>
[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')