主要牵涉到3个模块：
- logging
- logging.config
- logging.handles
| DEBUG | Detailed information, typically of interest only when diagnosing problems. |
| INFO | Confirmation that things are working as expected. |
| WARNING | An indication that something unexpected happened, or indicative of some problem in the near future (e.g. ‘disk space low’). The software is still working as expected. |
| ERROR | Due to a more serious problem, the software has not been able to perform some function. |
| CRITICAL | A serious error, indicating that the program itself may be unable to continue running. |
默认的是 WARNING
例子1：
import logging logging.warning('Watch out!') #会打印到控制台
logging.info('I told you so') # 什么也不打印
输出为：
WARNING:root:Watch out!
例子2：输出日志到文件
import logging logging.basicConfig(filename='example.log',level=logging.DEBUG) logging.debug('This message should go to the log file') logging.info('So should this') logging.warning('And this, too')
输出为（文件example.log的内容）：
DEBUG:root:This message should go to the log file INFO:root:So should this WARNING:root:And this, too
例子3：日志大小/文件数设置
import logging
import logging.handlers
import glob
LOG_FILENAME = 'logging_rotatingfile_example.out'
# Set up a specific logger with our desired output level
my_logger = logging.getLogger('MyLogger')
my_logger.setLevel(logging.DEBUG)
# Add the log message handler to the logger
handler = logging.handlers.RotatingFileHandler(
LOG_FILENAME, maxBytes=20, backupCount=5)
my_logger.addHandler(handler)
# Log some messages
for i in range(20):
my_logger.debug('i = %d' % i)
# See what files are created
logfiles = glob.glob('%s*' % LOG_FILENAME)
for filename in logfiles:
print(filename)
上面例子设置了单个日志最大文件大小20Byte，备份文件数为5个，也就时当前日志一个文件，和5个备份文件
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下一篇介绍logging日志格式的设定。。。