pandas.api.extensions.ExtensionArray._formatter#

ExtensionArray._formatter(boxed=False)[source]#

Formatting function for scalar values.

This is used in the default ‘__repr__’. The returned formatting function receives instances of your scalar type.

Parameters:

boxedbool, default False: An indicated for whether or not your array is being printed within a Series, DataFrame, or Index (True), or just by itself (False). This may be useful if you want scalar values to appear differently within a Series versus on its own (e.g. quoted or not).

Returns:

Callable[[Any], str]: A callable that gets instances of the scalar type and returns a string. By default, repr() is used when boxed=False and str() is used when boxed=True.

See also

api.extensions.ExtensionArray._concat_same_type: Concatenate multiple array of this dtype.
api.extensions.ExtensionArray._explode: Transform each element of list-like to a row.
api.extensions.ExtensionArray._from_factorized: Reconstruct an ExtensionArray after factorization.
api.extensions.ExtensionArray._from_sequence: Construct a new ExtensionArray from a sequence of scalars.

Examples

>>> class MyExtensionArray(pd.arrays.NumpyExtensionArray):
...     def _formatter(self, boxed=False):
...         return lambda x: "*" + str(x) + "*" if boxed else repr(x) + "*"
>>> MyExtensionArray(np.array([1, 2, 3, 4]))
<MyExtensionArray>
[1*, 2*, 3*, 4*]
Length: 4, dtype: int64