Not entirely the same thing, but there are some plugins for Vim, Emacs,... that show different figures/characters in place of things like "=>" or "lambda". But

Not entirely the same thing, but there are some plugins for Vim, Emacs,... that show different figures/characters in place of things like "=>" or "lambda". But don't actually change your source code. For example: https://github.com/ehamberg/vim-cute-python https://github.com/ehamberg/vim-cute-python