logging调试程序python

使用logging类记录错误

• 我们可以使用print()来调试程序，但如果到处是print()，想关闭又得一个个去修改。
• 使用logging类，我们可以记录各种级别的错误，通过配置参数，可以控制显示哪些错误记录。

错误级别：

• CRITICAL = 50
• FATAL = CRITICAL
• ERROR = 40
• WARNING = 30
• WARN = WARNING
• INFO = 20
• DEBUG = 10
• NOTSET = 0

  对应的方法：

• logging.critical()
• logging.fatal()
• logging.error()
• logging.warning()
• logging.warn()
• logging.info()

• logging.debug()

例子１　控制logging level为error

#!/usr/bin/python
# coding: utf-8

import logging

# logging.basicConfig(level=logging.NOTSET)
logging.basicConfig(level=logging.ERROR)

def cal(m, n):
    if n == 0:
        # raise ValueError('Illegal value: %d' % n)
        logging.info('Illegal value: %d' % n)
        
    logging.debug("debug_test")
    logging.warning("warning_test")
    logging.info("info_test")
    logging.error("error_test")
    logging.fatal("fatal_test")
    return  m * n

try:
    r = cal(6, 0)
    print(r)
except Exception as e:
    print(e)

输出：

ERROR:root:error_test
CRITICAL:root:fatal_test

例子2　控制logging level为WARNING

#!/usr/bin/python
# coding: utf-8

import logging

# logging.basicConfig(level=logging.NOTSET)
logging.basicConfig(level=logging.WARNING)

def cal(m, n):
    if n == 0:
        # raise ValueError('Illegal value: %d' % n)
        logging.info('Illegal value: %d' % n)
        
    logging.debug("debug_test")
    logging.warning("warning_test")
    logging.info("info_test")
    logging.error("error_test")
    logging.fatal("fatal_test")
    return  m * n

try:
    r = cal(6, 0)
    print(r)
except Exception as e:
    print(e)

输出：

WARNING:root:warning_test
ERROR:root:error_test
CRITICAL:root:fatal_test

例子３　控制logging level为DEBUG

#!/usr/bin/python
# coding: utf-8

import logging

# logging.basicConfig(level=logging.NOTSET)
logging.basicConfig(level=logging.DEBUG)

def cal(m, n):
    if n == 0:
        # raise ValueError('Illegal value: %d' % n)
        logging.info('Illegal value: %d' % n)
        
    logging.debug("debug_test")
    logging.warning("warning_test")
    logging.info("info_test")
    logging.error("error_test")
    logging.fatal("fatal_test")
    return  m * n

try:
    r = cal(6, 0)
    print(r)
except Exception as e:
    print(e)

输出：

INFO:root:Illegal value: 0
DEBUG:root:debug_test
WARNING:root:warning_test
INFO:root:info_test
ERROR:root:error_test
CRITICAL:root:fatal_test