Python decorator makes function forget that it belongs to a class

I am trying to write a decorator to do logging:

def logger(myFunc):
    def new(*args, **keyargs):
        print 'Entering %s.%s' % (myFunc.im_class.__name__, myFunc.__name__)
        return myFunc(*args, **keyargs)

    return new

class C(object):
    def f():


I would like this to print:

Entering C.f

but instead I get this error message:

AttributeError: 'function' object has no attribute 'im_class'

Presumably this is something to do with the scope of 'myFunc' inside 'logger', but I've no idea what.


Claudiu's answer is correct, but you can also cheat by getting the class name off of the self argument. This will give misleading log statements in cases of inheritance, but will tell you the class of the object whose method is being called. For example:

from functools import wraps  # use this to preserve function signatures and docstrings
def logger(func):
    def with_logging(*args, **kwargs):
        print "Entering %s.%s" % (args[0].__class__.__name__, func.__name__)
        return func(*args, **kwargs)
    return with_logging

class C(object):
    def f(self):


As I said, this won't work properly in cases where you've inherited a function from a parent class; in this case you might say

class B(C):

b = B()

and get the message Entering B.f where you actually want to get the message Entering C.f since that's the correct class. On the other hand, this might be acceptable, in which case I'd recommend this approach over Claudiu's suggestion.

Need Your Help

How to improve slow query using FILTER (?id IN ( … ) )

performance rdf sparql

I just started using SPARQL, and I'm trying to create a query that retrieves all information where an id has one of a number of predefined values? I have something like this :

git multiple indexes

git github-for-mac

I've been having issues with one of my git repos deleting all files on commit.

About UNIX Resources Network

Original, collect and organize Developers related documents, information and materials, contains jQuery, Html, CSS, MySQL, .NET, ASP.NET, SQL, objective-c, iPhone, Ruby on Rails, C, SQL Server, Ruby, Arrays, Regex, ASP.NET MVC, WPF, XML, Ajax, DataBase, and so on.