You are using Python2.7 in 2019. there is your problem. I understand if you inherited/maintaining a legacy application, you may not have had a choice about 2.7

You are using Python2.7 in 2019. there is your problem. I understand if you inherited/maintaining a legacy application, you may not have had a choice about 2.7, but if it's a significantly large project and you are not making any attempts to use Python3 (and many of the improvements that come with it, including optional typing as one commenter mentioned, don't blame language, unless you have a solution that is magically going to fix all the problems from a language that is pretty much in "maintainance-mode! please use the new version" mode).