After looking at this question I learned that the type hints are, by default, not enforced whilst executing Python code.
One can detect some discrepancies between the type hints and actual argument types using a slightly convoluted process of running pyannotate to generate stubs whilst running Python code, and scanning for differences after applying these stubs to the code.
However, it would be more convenient/faster to directly raise an exception if an incoming argument is not of the type included in the type hint. This can be achieved by manually including:
if not isinstance(some_argument, the_type_hint_type):
raise TypeError("Argument:{argument} is not of type:{the_type_hint_type}")
However, that is quite labour intensive. Hence, I was curious, is it possible to make Python raise an error if a type-hint is violated, using an CLI argument or pip package or something like that?
The edit queue for the Answer by @Surya_1897 is full, hence I will include a more detailed description of the solution here.
Typeguard does exactly what I was looking for. The following requirements apply:
pip install typeguard
@typechecked property above each function."""Some file description."""
def add_two(x:int):
"""Adds two to an incoming int."""
return x+2
somevar:float=42.1
add_two(somevar)
To:
"""Some file description."""
from typeguard import typechecked
@typechecked
def add_two(x:int):
"""Adds two to an incoming int."""
return x+2
somevar:float=42.1
add_two(somevar)
The latter will than throw an err:
TypeError: type of argument "x" must be int; got float instead