from types import FunctionType

def log(func):
    def function(*args,**kwargs):
        with open("logfile","a") as f:
            f.writelines(func.__name__ + str(args) + " " + str(kwargs) + str(func(*args,**kwargs)) + "\n")
    return function

class loggermetaclass(type):
    def __new__(meta, classname,supers, classdict):
        for attr, attrval in classdict.items():
            if type(attrval) is FunctionType and attr[0] != "_" and attr[1] !=  "_":
                classdict[attr] = log(attrval)
        return type.__new__(meta,classname,supers,classdict)


class logger():

    __metaclass__ = loggermetaclass

    def printint(self,k):
        return k
    def hello(self,string):
        return string

    def __str__(self):
        with open("logfile", "r") as f:
            text = f.read()
        return text

class blogger(logger):
    def popk(self,o):
        return o




m = blogger()
m.popk(9)