Overriding += to make a call.

gistfile1.py

class Bar:
    def __init__(self,inst,func,*args):
        self.inst = inst
        self.func = func
        self.args = args
    def __iadd__(self,*args,**kwargs):
        return self.__call__(*args,**kwargs)
    def __call__(self,*args,**kwargs):
        self.func(self.inst,*(self.args+args),**kwargs)

class Foo:
    def __init__(self):
        self.debug = Bar(self,self.log,"DEBUG")
        self.note  = Bar(self,self.log,"NOTE")
    def log(self,barself,level,msg):
        print "Level:",level
        print "Mesg :",msg

a= Foo()
a.debug("A")
a.note+="B"

output = """
Level: DEBUG
Mesg : A
Level: NOTE
Mesg : B
"""
raw_input()