python: enforcing type check on function using decorator

 

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

def typeassert(*ty_args, **ty_kwargs):         """         利用装饰器对函数参数强制性类型检查         enforcing type check on function using decorator         :param ty_args:         :param ty_kwargs:         :return:         """         def decorate(func):             # If in optimized mode, disable type checking             if not __debug__:                 return func               # Map function argument names to supplied types             sig = signature(func)             bound_types = sig.bind_partial(*ty_args, **ty_kwargs).arguments               @wraps(func)             def wrapper(*args, **kwargs):                 bound_values = sig.bind(*args, **kwargs)                 # Enforce type assertions across supplied arguments                 for name, value in bound_values.arguments.items():                     if name in bound_types:                         if not isinstance(value, bound_types[name]):                             raise TypeError(                                 'Argument {} must be {}'.format(name, bound_types[name])                             )                 return func(*args, **kwargs)               return wrapper           return decorate       @typeassert(int, z=int)     def spam(x, y, z=42):         """           :param y:         :param z:         :return:         """         print(x, y, z)   #https://github.com/yidao620c/python3-cookbook/blob/master/source/c09/p07_enforcing_type_check_on_function_using_decorator.rst