Python日志记录 - 防止日志事件被打印到控制台

Question

我不明白为什么日志事件正在打印到控制台，当我没有定义控制台处理程序。我读过的所有示例都明确定义了一个控制台处理程序（streamhandler），以便将消息输出到控制台。

我希望只将这些事件打印到文件中。

import logging 
logger = logging.getLogger(__name__) 

my_format = '%(asctime)-25s %(levelname)-8s LOGGER: %(name)-12s MODULE: %(module)-15s FUNCTION: %(funcName)-30s MSG: %(message)s' 
my_datefmt ='%m/%d/%Y %I:%M:%S%p' 
logging.basicConfig(format=my_format, datefmt=my_datefmt, level=logging.DEBUG) 
formatter = logging.Formatter(my_format, datefmt=my_datefmt) 
logger.setLevel(logging.DEBUG) 
handler1 = logging.FileHandler('mylog.txt') 
handler1.setLevel(logging.DEBUG) 
handler1.setFormatter(formatter) 
logger.addHandler(handler1) 

logger.debug("Why is this printed to the console") 

编辑：

有人指出，我并没有考虑到根记录。在调用logging.basicConfig时，默认的流处理程序被添加到根记录器（logger = getLogger（））

根记录器的处理程序可以修改，但是我发现我可以防止我的记录器传播日志到根记录器。

这是可以做到像这样：

import logging 
logger = logging.getLogger(__name__) 

my_format = '%(asctime)-25s %(levelname)-8s LOGGER: %(name)-12s MODULE: %(module)-15s FUNCTION: %(funcName)-30s MSG: %(message)s' 
my_datefmt ='%m/%d/%Y %I:%M:%S%p' 
logging.basicConfig(format=my_format, datefmt=my_datefmt, level=logging.DEBUG) 
formatter = logging.Formatter(my_format, datefmt=my_datefmt) 
logger.setLevel(logging.DEBUG) 
handler1 = logging.FileHandler('mylog.txt') 
handler1.setLevel(logging.DEBUG) 
handler1.setFormatter(formatter) 
logger.addHandler(handler1) 
logger.propagate = False    #### 
logger.debug("Why is this printed to the console") 

Answer 1

> ipython 
import logging 
logging.basicConfig? 

*****************logging.basicConfig************** 
Signature: logging.basicConfig(**kwargs) 
Docstring: 
Do basic configuration for the logging system. 

This function does nothing if the root logger already has handlers 
configured. It is a convenience method intended for use by simple scripts 
to do one-shot configuration of the logging package. 

The default behaviour is to create a StreamHandler which writes to 
sys.stderr, set a formatter using the BASIC_FORMAT format string, and 
add the handler to the root logger. 
... 

你有2个处理器。