# [Python-ideas] Boolean ABC similar to what's provided in the 'numbers' module

Sylvain MARIE sylvain.marie at schneider-electric.com
Mon Feb 12 04:41:04 EST 2018

```The numbers module provides very useful ABC for the 'numeric tower', able to abstract away the differences between python primitives and for example numpy primitives.
I could not find any equivalent for Booleans.
However numpy defines np.bool too, so being able to have an abstract Boolean class for both python bool and numpy bool would be great.

Here is a version that I included in valid8 in the meantime

-----------------------
class Boolean(metaclass=ABCMeta):
"""
An abstract base class for booleans, similar to what is available in numbers
see https://docs.python.org/3.5/library/numbers.html
"""
__slots__ = ()

@abstractmethod
def __bool__(self):
"""Return a builtin bool instance. Called for bool(self)."""

@abstractmethod
def __and__(self, other):
"""self & other"""

@abstractmethod
def __rand__(self, other):
"""other & self"""

@abstractmethod
def __xor__(self, other):
"""self ^ other"""

@abstractmethod
def __rxor__(self, other):
"""other ^ self"""

@abstractmethod
def __or__(self, other):
"""self | other"""

@abstractmethod
def __ror__(self, other):
"""other | self"""

@abstractmethod
def __invert__(self):
"""~self"""

# register bool and numpy bool_ as virtual subclasses
# so that issubclass(bool, Boolean) = issubclass(np.bool_, Boolean) = True
Boolean.register(bool)

try:
import numpy as np
Boolean.register(np.bool_)
except ImportError:
# silently escape
pass

---------------------------

If that topic was already discussed and settled in the past, please ignore this thread - apologies for not being able to find it.
Best regards

Sylvain

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-ideas/attachments/20180212/95ae8438/attachment.html>
```