pickle class instances with decorators on the class definitions about dill HOT 1 CLOSED

>>> def multiton(cls):
...   instances = {}
...   def getinstance(arg):
...     if arg not in instances:
...       instances[arg] = cls(arg)
...     return instances[arg]
...   return getinstance
... 
>>> @multiton
... class MyClass():
...   def __init__(self, arg):
...     self.arg = arg
... 
>>> import dill
>>> 
>>> a = MyClass('my arg')
>>> b = dill.loads(dill.dumps(a))
>>> a
<__main__.MyClass instance at 0x10bb50e18>
>>> b
<__main__.MyClass instance at 0x10bb50ea8>
>>> 
>>> a == b
False
>>> 
>>> a.arg      
'my arg'
>>> b.arg
'my arg'
>>> a.__class__ == b.__class__
False
>>> a.__class__
<class __main__.MyClass at 0x10b3afa78>
>>> b.__class__
<class __main__.MyClass at 0x10bb49460>
>>> import __main__ as _main_module
>>> _main_module.MyClass
<function getinstance at 0x10b3db668>
>>> 
>>> MyClass 
<function getinstance at 0x10b3db668>
>>>
>>> import copy
>>> copy.copy(a)
<__main__.MyClass instance at 0x10bb54fc8>
>>> copy.copy(b)
<__main__.MyClass instance at 0x10bada050>
>>> copy.copy(b) == copy.copy(a)
False
>>> copy.copy(b) == copy.copy(b)
False
>>> copy.deepcopy(b) == copy.deepcopy(b)
False
>>> copy.deepcopy(a) == copy.deepcopy(a)
False