class test:
def func_1(self):
pass
obj = test()
obj.func_1()
obj.func_1()
test.func_1(obj)
>>> a = 0
>>> a += 1
>>> b = 1
>>> a is b
True
>>> a = False
>>> a = not a
>>> b = True
a is b
True
>>> a = 1000
>>> a += 1
>>> b = 1001
>>> a is b
False