class decorator

class_decorator.py

class Tx(object):
    def __init__(self):
        print("Tx:init")
        self.something()

    def something(self):
        print("Tx:something")

    def otherthing(self):
        print("Tx:otherthing")

    def __call__(self, func):
        def wrapper(s, url_list):
            url_list.append(4)
            self.otherthing()
            return func(s, url_list)
        return wrapper


class v2(object):
    @Tx()
    def run(self, url_list):
        print("v2:run")
        print(url_list)


x = v2()
x.run([1, 2, 3])

#####
# OUTPUT
#
# Tx:init
# Tx:something
# Tx:otherthing
# v2:run
# [1, 2, 3, 4]
#
#####