for testing and deploying your application
for finding and fixing issues
for empowering human code reviews
from abc import ABC
__all__ = ['Singleton']
class Singleton(ABC):
_instance = None
def __new__(cls, *args, **kwargs):
if not cls._instance:
cls._instance = super(Singleton, cls).__new__(cls)
return cls._instance
if __name__ == '__main__':
class ObjectRegistry(Singleton):
x = super().__new__(cls)
if not getattr(x, 'objects', None):
x.objects = {}
return x
reg1 = ObjectRegistry()
reg1.objects['a'] = 1
reg2 = ObjectRegistry()
assert reg2.objects == {'a': 1}
reg2.objects['b'] = 2
reg3 = ObjectRegistry()
rs = [reg1, reg2, reg3]
assert id(reg1) == id(reg2) == id(reg3)
for i in rs:
print(i.objects)
assert i.objects == {'a': 1, 'b': 2}
assert all(x.objects == {'a': 1,
'b': 2} for x in rs)
del reg3.objects['a']
assert all(x.objects == {'b': 2} for x in rs)
assert i.objects == {'b': 2}
boromir674 /
so-magic
