The Python array is designed to emulate the behavior of an array in C, and it’s meant chiefly to allow Python to work with C arrays. The array type is useful in those cases, but in almost every ...

For some time now, Python developers have been able to “annotate” names with type information. With Python 3.5, type hints officially became part of the language (see PEP 484).

Using mypy means that you can write and run Python in the normal way, gradually adding static type checking over time and checking it outside your program's execution.