hasattr_test.py

# -*- coding: utf-8 -*-

class OldRobot():
    def __init__(self):
        self.speed = 5

    def walk(self):
        print("old robot walking {} km/h.".format(self.speed))

class NewRobot():
    def __init__(self):
        self.speed = 20

    def run(self):
        print("new robot running {} km/h.".format(self.speed))

robots = [OldRobot(), NewRobot()]
for robot in robots:
    if hasattr(robot, "walk"):
        robot.walk()
    if hasattr(robot, "run"):
        robot.run()

# old robot walking 5 km/h.
# new robot running 20 km/h.