4.2. Annotating existing code

4.2.1. PyAnnotate

Code 4.160. the -w flag means "go ahead, update the file"
$ pip install pyannotate
$ pyannotate -w FILE

4.2.2. monkeytype

$ pip install monkeytype
$ monkeytype run runtests.py
$ monkeytype stub some.module
$ monkeytype apply some.module