Here Ctrl+D⌘D is used to select the next occurrence of the current word.
Here Ctrl+Shift+L⇧⌘L is used to split a selection into lines, and each line is then edited simultaneously.
Here Ctrl+Shift+P⇧⌘P is used to show the Command Palette, "sspy" (short for Set Syntax: Python) is used set the syntax of the current file to Python.
Ctrl+P⌘P shows Goto Anything, and typing then filters on file and directory names.
Type @ after a file name to filter on symbols. More...
Here unwanted whitespace is removed by using the regex " +" to find groups of spaces, which are then selected simultaneously with the Find All button.