如何在Python 3中区分实例方法，类方法，静态方法或函数? [英] How to distinguish an instance method, a class method, a static method or a function in Python 3?

问题描述

我想在Python 3中区分方法和函数.此外，如果它是一个方法，我想获得相应的类.我当前的解决方案是这样的:

I want to distinguish between methods and functions in Python 3. Furthermore, I want to get the corresponding class if it is a method. My current solution is like this:

import types
import inspect

def function_or_method(f):
    if inspect.ismethod(f):
        if inspect.isclass(f.__self__):
            print("class method")
            klass = f.__self__
        else:
            print("instance method")
            klass = f.__self__.__class__
    elif inspect.isfunction(f): # function
        if f.__name__ != f.__qualname__: # to distiguish staticmethod and function
            print("static method")
            # HOW TO GET THE CLASS
        else:
            print("function")
    else:
        print("not function or method")

class Foo():
    def bari(self):
        pass
    @classmethod
    def barc(cls):
        pass
    @staticmethod
    def bars():
        pass

def barf():
    pass

function_or_method(Foo().bari) # instance method
function_or_method(Foo.barc) # class method
function_or_method(Foo.bars) # static method
function_or_method(barf) # function

它可以工作，但是看起来并不优雅.而且我不确定我是否错过了什么.有谁知道更好的解决方案?

It works, but it looks not elegant. And I am not sure whether I have missed something. Does anyone know a better solution?

更新1 :如果它是方法，我也想获得相应的类.我知道如何处理类/实例方法(请参见上面的代码)，但是如何获取静态方法的类?

UPDATE 1: I also want to get the corresponding class if it is a method. I know how to deal with class/instance method(see the above code), but how can I get the class for the static method?

推荐答案

您只需要获取方法的类型，但是由于方法是描述符，因此您必须:

You just need to get the type of the method, but since methods are descriptors, you have to :

1-将类从实例中取出. 2-在__dict__中查找方法引用，而不是进行属性查找.

1 - Get the class out of the instance. 2 - Look up the method reference in __dict__ instead of making an attribute lookup.

E.G:

>>> f = Foo()
>>> type(f.__class__.__dict__['bari'])
<class 'function'>
>>> type(f.__class__.__dict__['barc'])
<class 'classmethod'>
>>> type(f.__class__.__dict__['bars'])
<class 'staticmethod'>

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