Python documentation says that "To build structures with non-native byte order, you can use one of the BigEndianStructure, LittleEndianStructure, BigEndianUnion, and LittleEndianUnion base classes"

However, BigEndianUnion ad LittleEndianUnion are not implemented

>>> from ctypes import *
>>> BigEndianStructure
<class 'ctypes._endian.BigEndianStructure'>
>>> BigEndianUnion
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'BigEndianUnion' is not defined

Is that something that can be added?

See also https://bugs.python.org/issue19023