logging調試程序python

使用logging類記錄錯誤

• 我們可以使用print()來調試程序，但如果到處是print()，想關閉又得一個個去修改。
• 使用logging類，我們可以記錄各種級別的錯誤，通過配置參數，可以控制顯示哪些錯誤記錄。

錯誤級別：

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

  對應的方法：

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

• logging.debug()

例子１　控制logging level爲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)

輸出：

ERROR:root:error_test
CRITICAL:root:fatal_test

例子2　控制logging level爲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)

輸出：

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

例子３　控制logging level爲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)

輸出：

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