Python

Python 3.6 type checking

Make sure python is 3.6 or above

 python3 -m pip install -U mypy

Example code with typecheck

from typing import List
Vector = List[float]

def scale(scalar: float, vector: Vector) -> Vector:
    return [scalar * num for num in vector]
	
# typechecks; a list of floats qualifies as a Vector.
new_vector = scale(2.0, [1.0, -4.2, 5.4])
print(new_vector)

To test typing, just run

mypy testtype.py