collections github programs lists changing contents - copying command-line arguments - execution commands creating interp command doubly linked lists - moving data between - program commandsstrategy pattern - slicing queuing spacing setsusing tuples comma-separated numbers comments docstrings returning indentation using spacing color color changing program exampleobserver pattern - tkinter libraryapplying color with combining arithmetic/assignment statements common mistakespython decision making communicating between classes comparison operators - compilingsimple python program example conditions complement operator - dictionaries complete python programswriting combo boxes - complex numbers command pattern composite pattern buttoncommand objects boss class buttons caching results creating undo button - command objects building - calling - containers mediators and - composite implementation consequences of doubly linked lists - employee class - employee trees building printing - consequences of github programs github programs iterators keyboard example - leaf nodes - keymoderator class recursive calls stet references salary computation undo function - simple composites treeviews of composites -