Python 在被调用函数中捕获参数异常

一般情况下, python 无法捕获被调用函数的参数异常, 但是用装饰器可以实现此功能.

先定义一个 check 装饰器:

import traceback
import sys

def check(method):
    '''
    check argument
    '''
    def wrapper(*args, **kw):
        try:
            return method(*args, **kw)
        except TypeError as e:
            print("I catch you!")
            stack = traceback.format_list(traceback.extract_stack())
            for line in stack:
                print('>> '+line.strip())
            print(sys.exc_info())

    return wrapper

再把要被调用的函数加上装饰器:

@check
def hello(msg):
        print(msg)

hello()

输出如下, 可以看到, check 装饰器已经捕获到 TypeError 异常了