Python Logging is a built-in logging module that allows you to log your application's debug information for easy troubleshooting during development and deployment.
log level
| grade | value | illustrate |
|---|---|---|
| logging.CRITICAL | 50 | Critical error, indicating that the software cannot continue to run. |
| logging.ERROR | 40 | Error message that the software can no longer perform some functions due to more serious problems. |
| logging.WARNING | 30 | Default levels , notifications for some unforeseen events, or problems that may arise in the future. For example: Insufficient disk space. But the software will still work as usual. |
| logging.INFO | 20 | expected information |
| logging.DEBUG | 10 | debug information |
| logging.NOTSET | 0 | not set |
Log level: debug < info < warning < error < critical
They all have corresponding functions to output to the console or file.
Print the log of the corresponding level:
import logging
logging.basicConfig(level=logging.DEBUG)
logging.debug('This is a debug message')
logging.info('This is an info message')
logging.warning('This is a warning message')
logging.error('This is an error message')
logging.critical('This is a critical message')
Use the basicConfig method to configure logging and set the log level to DEBUG.
Configure log format, output to file
logging.basicConfig(level=logging.DEBUG, # 控制台打印的日志级别
filename='202308.log',
filemode='a', # 模式，有w和a，w就是写模式，每次都会重新写日志，覆盖之前的日志
# a是追加模式，默认如果不写的话，就是追加模式
format='%(asctime)s - %(pathname)s[line:%(lineno)d] - %(levelname)s: %(message)s'
# 日志格式
2023-08-04 18:42:40,063 - D:\test1.py[line:12] - DEBUG: This is a debug message
2023-08-04 18:42:40,064 - D:\test1.py[line:13] - INFO: This is an info message
2023-08-04 18:42:40,064 - D:\test1.py[line:14] - WARNING: This is a warning message
2023-08-04 18:42:40,064 - D:\test1.py[line:15] - ERROR: This is an error message
2023-08-04 18:42:40,064 - D:\test1.py[line:16] - CRITICAL: This is a critical message
reference
https://docs.python.org/3/library/logging.html#logrecord-attributes