JAVA高级面试进阶训练营视频教程

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当脚本中需要进行的的相同的异常操作很多的时候，可以用修饰器来简化代码。比如我需要记录抛出的异常：

在log_exception.py文件中，

import functools
import logging

def create_logger():
    logger = logging.getLogger("test_log")
    logger.setLevel(logging.INFO)
    fh = logging.FileHandler("test.log")
    fmt = "[%(asctime)s-%(name)s-%(levelname)s]: %(message)s"
    formatter = logging.Formatter(fmt)
    fh.setFormatter(formatter)
    logger.addHandler(fh) 
    return logger

def log_exception(fn):
    @functools.wraps(fn)
    def wrapper(*args, **kwargs):
        logger = create_logger()
        try:
            fn(*args, **kwargs)
        except Exception as e:
            logger.exception("[Error in {}] msg: {}".format(__name__, str(e)))
            raise
    return wrapper

在test.py文件中：

from log_exception import log_exception

@log_exception
def reciprocal(x):
    return 1/x

if __name__ == "__main__"：
    reciprocal(0)

在test.log文件中可以看到以下错误信息：

[2017-11-26 23:37:41,012-test_log-ERROR]: [Error in __main__] msg: integer division or modulo by zero
Traceback (most recent call last):
  File "<ipython-input-43-cfa2d18586a3>", line 16, in wrapper
    fn(*args, **kwargs)
  File "<ipython-input-46-37aa8ff0ba48>", line 3, in reciprocal
    return 1/x
ZeroDivisionError: integer division or modulo by zero

参考：

1. https://wiki.python.org/moin/PythonDecorators
2. https://www.blog.pythonlibrary.org/2016/06/09/python-how-to-create-an-exception-logging-decorator/