An example of argument validation without using pydantic

non_pydantic_validation_example.py

import math
from dataclasses import dataclass


@dataclass
class Point:
    x: int
    y: int


def compute_distance(a: Point, b: Point) -> float:
    if not isinstance(a, Point):
        raise TypeError
    if not isinstance(b, Point):
        raise TypeError

    x = math.pow(a.x - b.x, 2)
    y = math.pow(a.y - b.y, 2)
    return math.sqrt(x + y)


p1 = Point(1, 2)
p2 = Point(3, 5)

print('distance between p1 and p2 is:', compute_distance(p1, p2))