structural patterns doubly linked lists - flyweightsdefined employee class - folders as flyweights - github programs github programs iterators selecting folders - leaf nodes - proxy pattern printing employee trees - comparing related patterns - recursive calls stet copy-on write objects salary computation github programs simple composites pildisplaying images treeviews of composites - pilusing - decorator pattern buttons - consequences of - threadsloading images - threadslogging from summary of dataclass decorator - subclassesfactory pattern - decorated code - suffix/prefix removal decorator class - github programs swimmer classfactory method pattern - nonvisual decorators - switch statements see match function facade pattern - building classes - consequences of switching between states syntaxpython classes creating databases - blank lines creating tables - docstrings database class - indentation database objects naming conventions dbobjects github programs mysql database connections comments docstrings spacing mysql workbench complex numbers query class - constants results class character constants - sqlite named constants see variables table class naming conventions tables names - flyweight pattern copy-on write objects example code - numeric constants data types equal signs (=initialization with spacing