iframe-proxy | Sunbelt Computer Software

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#!/usr/bin/env python
# -*- coding: utf-8 -*-
Encapsulates all information needed to perform an action or trigger an event.
*Examples in Python ecosystem:
Django HttpRequest (without `execute` method):
 https://docs.djangoproject.com/en/2.1/ref/request-response/#httprequest-objects
from __future__ import print_function
class MoveFileCommand(object):
    def __init__(self, src, dest):
        self.src = src
        self.dest = dest
    def execute(self):
        self.rename(self.src, self.dest)
    def undo(self):
        self.rename(self.dest, self.src)
    def rename(self, src, dest):
        print(u"renaming %s to %s" % (src, dest))
        os.rename(src, dest)
def main():
    >>> from os.path import lexists
    >>> command_stack = [
    ...     MoveFileCommand('foo.txt', 'bar.txt'),
    ...     MoveFileCommand('bar.txt', 'baz.txt')
    # Verify that none of the target files exist
    >>> assert not lexists("foo.txt")
    >>> assert not lexists("bar.txt")
    >>> assert not lexists("baz.txt")
    # Create empty file
    >>> open("foo.txt", "w").close()
    # Commands can be executed later on
    >>> for cmd in command_stack:
    ...     cmd.execute()
    renaming foo.txt to bar.txt
    renaming bar.txt to baz.txt
    # And can also be undone at will
    >>> for cmd in reversed(command_stack):
    ...     cmd.undo()
    renaming baz.txt to bar.txt
    renaming bar.txt to foo.txt
    >>> os.unlink("foo.txt")
if __name__ == "__main__":
    import doctest
    doctest.testmod()

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