import logging
<p>logging.basicConfig(level=logging.INFO)
logging.info("这是一条 info 级别的日志")</p>

import logging
<p>logging.basicConfig(
level=logging.DEBUG,
format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
handlers=[
logging.FileHandler("app.log"),
logging.StreamHandler()  # 输出到控制台
]
)</p>

logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)
<h1>防止重复添加 handler</h1><p>if not logger.handlers:
handler = logging.StreamHandler()
formatter = logging.Formatter('%(name)s - %(levelname)s - %(message)s')
handler.setFormatter(formatter)
logger.addHandler(handler)</p><p>logger.info("来自 %s 模块的信息", <strong>name</strong>)</p>

import logging.config
<p>LOGGING_CONFIG = {
'version': 1,
'disable_existing_loggers': False,
'formatters': {
'detailed': {
'format': '%(asctime)s [%(levelname)s] %(name)s: %(message)s'
},
'simple': {
'format': '%(levelname)s %(message)s'
}
},
'handlers': {
'console': {
'class': 'logging.StreamHandler',
'level': 'INFO',
'formatter': 'simple',
'stream': 'ext://sys.stdout'
},
'file': {
'class': 'logging.FileHandler',
'level': 'DEBUG',
'formatter': 'detailed',
'filename': 'debug.log',
'mode': 'a'
}
},
'loggers': {
'myapp': {
'level': 'DEBUG',
'handlers': ['console', 'file'],
'propagate': False
}
},
'root': {
'level': 'WARNING',
'handlers': ['file']
}
}</p><p>logging.config.dictConfig(LOGGING_CONFIG)
logger = logging.getLogger('myapp')
logger.debug("这是从 myapp 记录器输出的调试信息")</p>