Dropbox is very heavily invested in Python. I am under impression they hired Guido van Rossum to do exactly this, among other things. First 100% statically type

Dropbox is very heavily invested in Python. I am under impression they hired Guido van Rossum to do exactly this, among other things. First 100% statically type the old codebase, then port it to Python 3. You can statically type Python 2 codebases, but the language does not offer native support for it. Thus, all needs to go to docstrings or comments.