validators.py 文件源码

def declare_schema(**schemas):
    """Declares data schema for function arguments.

    :param schemas: the mapping, where key is argument name, value is schema
                    the schema may be callable object or method of class
                    in this case the wrapped function should be method of
                    same class
    :raises ValueError: if the passed data does not fit declared schema
    """

    def decorator(func):
        validators = {k: _build_validator(v) for k, v in schemas.items()}
        defaults = _get_default_arguments(func)

        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            bound_args = inspect.getcallargs(func, *args, **kwargs)
            for n, v in bound_args.items():
                if v is not defaults.get(n, _SENTINEL) and n in validators:
                    validators[n](args and args[0] or None, v)
            return func(*args, **kwargs)
        return wrapper
    return decorator