In my last article, I introduced Mypy, a package that enforces type checking inPython programs. Python itself is, and always will remain, adynamically typed language. However, Python 3 supports “annotations”, afeature that allows you to attach an object to variables, functionparameters and function return values. These annotations are ignored byPython itself, but they can be used by external tools.

Source: LXer – Python’s Mypy–Advanced Usage