用python装饰器完成一个参数检查器

Question

用python装饰器完成一个参数检查器，若参数是整形 数字在0-10之间，若是字符串 长度在8-16之间 若是数组list 则要求类型都是字符串 其他类型默认参数不能为空。如果校验不通过，则抛异常，通过则继续执行

Answer 1

import collections
import functools
import inspect

def para_check(func):
msg = 'Argument {argument} must be {expected!r},but got {got!r},value {value!r}'

# 获取函数定义的参数
sig = inspect.signature(func)
parameters = sig.parameters     # 参数有序字典
arg_keys = tuple(parameters.keys())
@functools.wraps(func)
def wrapper(*args, **kwargs):
    CheckItem = collections.namedtuple('CheckItem', ('anno', 'arg_name', 'value'))
    check_list = []

    # collect args  *args 传入的参数以及对应的函数参数注释
    for i, value in enumerate(args):
        arg_name = arg_keys[i]
        anno = parameters[arg_name].annotation
        check_list.append(CheckItem(anno, arg_name, value))

    # collect kwargs **kwargs 传入的参数以及对应的函数参数注释
    for arg_name, value in kwargs.items():
        anno = parameters[arg_name].annotation
        check_list.append(CheckItem(anno, arg_name, value))

    # check type
    for item in check_list:
        if not isinstance(item.value, item.anno):
            error = msg.format(expected=item.anno, argument=item.arg_name,
                               got=type(item.value), value=item.value)
            raise TypeError(error)
    return func(*args, **kwargs)
return wrapper

@para_check
def test(x: int, y: int):
return x + y

test('1', 2)

1. 执行结果
   C:\Users\HuJun\PycharmProjects\pythonProject\venv\Scripts\python.exe "F:\PyCharm\PyCharm 2021.1.1\plugins\python\helpers\pydev\pydevd.py" --multiproc --qt-support=auto --client 127.0.0.1 --port 3899 --file C:/Users/HuJun/PycharmProjects/pythonProject/daily_tesy/decorate_check.py
   Connected to pydev debugger (build 211.7142.13)
   Traceback (most recent call last):
   File "F:\PyCharm\PyCharm 2021.1.1\plugins\python\helpers\pydev\pydevd.py", line 1483, in _exec
   pydev_imports.execfile(file, globals, locals) # execute the script
   File "F:\PyCharm\PyCharm 2021.1.1\plugins\python\helpers\pydev_pydev_imps_pydev_execfile.py", line 18, in execfile
   exec(compile(contents+"\n", file, 'exec'), glob, loc)
   File "C:/Users/HuJun/PycharmProjects/pythonProject/daily_tesy/decorate_check.py", line 48, in
   test('1', 2)
   File "C:/Users/HuJun/PycharmProjects/pythonProject/daily_tesy/decorate_check.py", line 38, in wrapper
   raise TypeError(error)
   TypeError: Argument x must be <class 'int'>,but got <class 'str'>,value '1'
   python-BaseException

Process finished with exit code 1