with_checks.py

import inspect
def with_checks(checks):
    def wrapper(func):
        def wrapped(*args, **kwargs):
            bound_args = inspect.signature(func).bind(*args, **kwargs)
            errors = list()
            for check in checks:
                decorator_params = inspect.signature(check).parameters.keys()
                matching_params = [(sym, bound_args.arguments[sym]) for sym in decorator_params if sym in bound_args.arguments.keys()]
                if len(matching_params) > 0:
                    if not check(*[arg for _, arg in matching_params]):
                        errors.append(matching_params)
            if len(errors) > 0:
                raise ValueError("{fun}: argument(s) have bad value: {values}".format(fun=func.__name__, values=errors))
            return func(*args, **kwargs)
        return wrapped
    return wrapper
  
@with_checks([lambda a: a > -1, lambda b: b > -1])
def addPositive(a,b): return a + b

@with_checks([lambda first_name: len(first_name) < 5, lambda last_name: len(last_name) < 7])
def onlyShortNamePls(first_name, last_name): print("Hello there {first} {last}".format(first=first_name, last=last_name))