Validate kwargs in Python without external dependencies

validate.py

# Somewhere on your project: foo/validate.py
from functools import wraps


def validate_kwargs(*checks, required=()):
    def decorator(func):
        @wraps(func)
        def wrapper(**kwargs):
            for key, check, expected in checks:
                if key in kwargs and not check(kwargs[key], expected):
                    raise ValueError(
                        f"Failed validation ({key}, {check.__name__}, {expected})"
                    )
            for key in required:
                if key not in kwargs:
                    raise TypeError(f"required: {', '.join(required)}")
            return func(**kwargs)

        return wrapper

    return decorator


# Your code
# from foo.validate import validate_kwargs

import operator


@validate_kwargs(
    ("name", isinstance, str),
    ("age", isinstance, int),
    ("team", isinstance, int),
    ("team", operator.gt, 5),
    required=("name", "age"),
)
def my_function(**kwargs):
    print(kwargs)


my_function()
# TypeError:required: name, age

my_function(name="Bruno")
# TypeError: required age

my_function(name="Bruno", age=21, team=2)
# ValueError: Failed validation (team, operator.gt, 5)

my_function(name="Bruno", age=21, team=10)
# {'name': 'Bruno', 'age': 21, 'team': 10}