def __init__(selfwindow)self window window def execute(self)self window exit(these commands are straightforwardthey demonstrate the basic patternbut it is important to note that we can store state and other information with the command if necessary for exampleif we had command to insert characterwe could maintain state for the character currently being inserted now all we have to do is hook up some client and test code to make the commands work for basic testingwe can just include this at the end of the scriptwindow window(document document("a_document txt"save savecommand(documentexit exitcommand(windowsave_button toolbarbutton('save''save png'save_button command save save_keystroke keyboardshortcut(" ""ctrl"save_keystroke command save exit_menu menuitem("file""exit"exit_menu command exit first we create two receivers and two commands then we create several of the available invokers and set the correct command on each of them to testwe can use python - filename py and run code like exit_menu click()which will end the programor save_keystroke keystroke()which will save the fake file unfortunatelythe preceding examples do not feel terribly pythonic they have lot of "boilerplate code(code that does not accomplish anythingbut only provides structure to the pattern)and the command classes are all eerily similar to each other perhaps we could create generic command object that takes function as callbackin factwhy bothercan we just use function or method object for each commandinstead of an object with an execute(methodwe can write function and use that as the command directly this is common paradigm for the command pattern in pythonimport sys class window