Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
359 views
in Technique[技术] by (71.8m points)

python - How to distinguish between a function and a class method?

If a variable refers to either a function or a class method, how can I find out which one it is and get the class type in case it is a class method especially when the class is still being declared as in the given example.

eg.

def get_info(function_or_method):
    print function_or_method

class Foo(object):
    def __init__(self):
        pass

    get_info(__init__)

def bar():
    pass

get_info(bar)

Update to question after the first two responses from David and J. F. Sebastian To reemphasize a point which J.F. Sebastian alluded to, I want to be able to distinguish it when the function is being declared within the class (when the type I am getting is a function and not a bound or unbound method). ie. where the first call to get_info(__init__) happens I would like to be able to detect that its a method being declared as a part of a class.

This question came up since I am putting a decorator around it and it gets a handle to the init function and I can't actually figure out if a method is being declared within a class or as a stand alone function

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can distinguish between the two by checking the type:

>>> type(bar)
<type 'function'>
>>> type(Foo.__init__)
<type 'instancemethod'>

or

>>> import types
>>> isinstance(bar, types.FunctionType)
True
>>> isinstance(bar, types.UnboundMethodType)
True

which is the way you'd do it in an if statement.

Also, you can get the class from the im_class attribute of the method:

>>> Foo.__init__.im_class
__main__.Foo

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

1.4m articles

1.4m replys

5 comments

57.0k users

...