python面试

题目描述

 # 有一个函数bar()，偶尔会抛出超时异常（TimeoutError) # 请完成retry，使bar()在遇到这种异常时可以重试指定的次数 (1p) def retry(exception: Exception, max_retries: int):     pass ​ class TimeoutError(Exception):     pass ​ @retry(TimeoutError, 10) def bar(*args, **kwargs):     import random     if random.random() < 0.5:         raise TimeoutError("bar failed")

解答1

 # 典型的装饰器，但是这个是带参数的装饰器 from functools import wraps def retry(exception: Exception, max_retires: int):     def func_wrapper(func):         @wraps(func)         def wrapper(*args, **kwargs):             for _ in range(max_retires):                 try:                     return func(*args, **kwargs)                 except exception:                     print(f"_ is {_+1}尝试")             return None ​         return wrapper ​     return func_wrapper

解答2

 class Retry:     def __init__(self, exception: Exception, max_retires: int) -> None:         self.exception = exception         self.max_retires = max_retires ​     def __call__(self, func):         @wraps(func)         def wrapper(*args, **kwargs):             for _ in range(self.max_retires):                 try:                     return func(*args, **kwargs)                 except self.exception:                     print(f"第{_+1}次尝试")             return None ​         return wrapper