GoF design pattern - Command

command.py

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

import os

class MoveFileCommand(object):
	def __init__(self, src, dest):
		self.src = src
		self.dest = dest

	def execute(self):
		self()

	def __call__(self):
		print("renaming {} to {}".format(self.src, self.dest))
		os.rename(self.src, self.dest)

	def undo(self):
		print("renaming {} to {}".format(self.dest, self.src))
		os.rename(self.dest, self.src)


def main():
	command_stack = []

	# commands are jsust pushed into the command stack
	command_stack.append(MoveFileCommand("foo.txt", "bar.txt"))
	command_stack.append(MoveFileCommand("bar.txt", "baz.txt"))

	for cmd in command_stack:
		cmd.execute()

	for cmd in reversed(command_stack):
		cmd.undo()


if __name__ == "__main__":
	main()