singletonify

install

pip install singletonify

usage

from singletonify import singleton

@singleton(a=3)
class YourClass:
    def __init__(self, a): ...

assert YourClass() is YourClass()

why not other

There are many singleton libraries on pypi, but their all has problem:

• singleton - cannot use issubclass() or __mro__ or ...
• singleton-decorator - cannot use isinstance() .
• singleton_factory - wtf, why do people use dict()[hash(obj)] = obj ?
• singletonmetaclasss - a little like this, but not a decorator.
• singleton3 - haha
• pysingleton - ABANDONED.