Today I learned how to do multiline input in the REPL using an uncommon combination of arguments for the built-in open.
Today I learned that the module builtins grows dynamically in the REPL.
Today I learned how to debug the new Python REPL with _pyrepl.trace and the environment variable PYREPL_TRACE.
Today I learned how to fix an issue with Ctrl+left and Ctrl+right not working in the new Python REPL on MacOS.
