Shared via mypy Playground

main.py

def func_with_kw_only(x: int, *, y: int = 0):
    return x + y
    
def func_with_pos_only(x: int, y: int, /):
    return x + y
    
    
func_with_kw_only(1)  # OK
func_with_kw_only(1, y=2)  # OK
func_with_kw_only(1, 2)  # error: Too many positional arguments for "func_with_kw_only"  [call-arg]

func_with_pos_only(1, 2)  # OK
func_with_pos_only(1, y=2)  # error: Unexpected keyword argument "y" for "func_with_pos_only"  [call-arg]