区分函数与方法

def func():
    pass

class Animal(object):

    def run(self):
        pass

print(func)  # <function func at 0x0000022343CD1F28>

c = Animal()
print(c.run)  # <bound method Animal.run of <__main__.Animal object at 0x0000022344128400>>

from types import FunctionType, MethodType


class Foo(object):

    def run(self):
        pass


fn = Foo()
print(isinstance(fn.run, MethodType))     # True
print(isinstance(Foo.run, FunctionType))  # True

from types import FunctionType, MethodType


class Foo(object):

    @staticmethod
    def run():
        pass

fn = Foo()
print(isinstance(fn.run, FunctionType))   # True
print(isinstance(Foo.run, FunctionType))  # True

from types import FunctionType, MethodType


class Foo(object):

    @classmethod
    def run(cls):
        pass

fn = Foo()
print(isinstance(fn.run, MethodType))   # True
print(isinstance(Foo.run, MethodType))  # True