SPC p %: projectile-replace-regexp: can replace string by regex express among all files in one project. Useful for function renaming.
C-o: back to previous cursor location. Useful after jumping to the definition of some specific function.
S j i: jump in buffer
C-c <: python indent shift left. move code block to left.
[ e: move line up.
S v v s ": surround word with double quote.