pvv
Minimal Python decorator to enforce type validation from type hints
Installation
This library has been created to have zero dependencies, and work with native Python. Use your favorite package manager to install pvv from PyPI.
pip install pvv
Usage
There are two ways to use the validate decorator from pvv:
Validate all parameters
Just use the decorator. A TypeError will be raised if the function is called with parameters of incorrect type.
Note
pvv will check if the given parameters to a function are instances of the class annotated as a parameter. If one parameter has no type hints, it will be ignored in the validation.
Warning
pvv will only work with type hints that can be used with class and instance checks.
from pvv import validate
@validate
def function(a: str, b: int, c):
pass>>> function("a", 3, 2)
>>> function(c=2, a="a", b=2)
>>> function(3, "a", 2)
TypeError: Incorrect type of function arguments: 'a' must be of type 'str', 'b' must be of type 'int'
Validate some parameters
from pvv import validate
@validate('a', 'c')
def function(a: str, b: int, c: bool | None):
pass>>> function("a", 3, True)
>>> function(3, "b", 0)
TypeError: Incorrect type of function arguments: 'a' must be of type 'str', 'c' must be of type 'bool | None'
An important note
The parameters of the validate decorator must all be of type str, otherwise a ValidatorError will be raised:
>>> @validate('a', 1)
... def func(*args, **kwargs):
... pass
pvv.exceptions.ValidatorError: All arguments of decorator must be of type 'str'
