从IPython Notebook中的日志记录模块获取输出

问题:从IPython Notebook中的日志记录模块获取输出

当我在IPython Notebook中运行以下命令时,看不到任何输出:

import logging
logging.basicConfig(level=logging.DEBUG)
logging.debug("test")

有人知道怎么做,这样我才能在笔记本中看到“测试”消息吗?

When I running the following inside IPython Notebook I don’t see any output:

import logging
logging.basicConfig(level=logging.DEBUG)
logging.debug("test")

Anyone know how to make it so I can see the “test” message inside the notebook?


回答 0

请尝试以下操作:

import logging
logger = logging.getLogger()
logger.setLevel(logging.DEBUG)
logging.debug("test")

根据logging.basicConfig

通过创建带有默认Formatter的StreamHandler并将其添加到根记录器,对记录系统进行基本配置。如果没有为根记录器定义处理程序,则debug(),info(),warning(),error()和critical()函数将自动调用basicConfig()。

如果根记录器已经为其配置了处理程序,则此功能不执行任何操作。

似乎ipython笔记本在某处调用basicConfig(或设置处理程序)。

Try following:

import logging
logger = logging.getLogger()
logger.setLevel(logging.DEBUG)
logging.debug("test")

According to logging.basicConfig:

Does basic configuration for the logging system by creating a StreamHandler with a default Formatter and adding it to the root logger. The functions debug(), info(), warning(), error() and critical() will call basicConfig() automatically if no handlers are defined for the root logger.

This function does nothing if the root logger already has handlers configured for it.

It seems like ipython notebook call basicConfig (or set handler) somewhere.


回答 1

如果仍要使用basicConfig,请像这样重新加载日志记录模块

from importlib import reload  # Not needed in Python 2
import logging
reload(logging)
logging.basicConfig(format='%(asctime)s %(levelname)s:%(message)s', level=logging.DEBUG, datefmt='%I:%M:%S')

If you still want to use basicConfig, reload the logging module like this

from importlib import reload  # Not needed in Python 2
import logging
reload(logging)
logging.basicConfig(format='%(asctime)s %(levelname)s:%(message)s', level=logging.DEBUG, datefmt='%I:%M:%S')

回答 2

我的理解是IPython会话开始记录日志,因此basicConfig不起作用。这是对我有用的设置(我希望这看起来不太好,因为我想将其用于几乎所有笔记本电脑):

import logging
logger = logging.getLogger()
fhandler = logging.FileHandler(filename='mylog.log', mode='a')
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
fhandler.setFormatter(formatter)
logger.addHandler(fhandler)
logger.setLevel(logging.DEBUG)

现在,当我运行时:

logging.error('hello!')
logging.debug('This is a debug message')
logging.info('this is an info message')
logging.warning('tbllalfhldfhd, warning.')

我在与笔记本相同的目录中得到一个“ mylog.log”文件,其中包含:

2015-01-28 09:49:25,026 - root - ERROR - hello!
2015-01-28 09:49:25,028 - root - DEBUG - This is a debug message
2015-01-28 09:49:25,029 - root - INFO - this is an info message
2015-01-28 09:49:25,032 - root - WARNING - tbllalfhldfhd, warning.

请注意,如果您在不重新启动IPython会话的情况下重新运行它,则会将重复的条目写入文件,因为现在将定义两个文件处理程序

My understanding is that the IPython session starts up logging so basicConfig doesn’t work. Here is the setup that works for me (I wish this was not so gross looking since I want to use it for almost all my notebooks):

import logging
logger = logging.getLogger()
fhandler = logging.FileHandler(filename='mylog.log', mode='a')
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
fhandler.setFormatter(formatter)
logger.addHandler(fhandler)
logger.setLevel(logging.DEBUG)

Now when I run:

logging.error('hello!')
logging.debug('This is a debug message')
logging.info('this is an info message')
logging.warning('tbllalfhldfhd, warning.')

I get a “mylog.log” file in the same directory as my notebook that contains:

2015-01-28 09:49:25,026 - root - ERROR - hello!
2015-01-28 09:49:25,028 - root - DEBUG - This is a debug message
2015-01-28 09:49:25,029 - root - INFO - this is an info message
2015-01-28 09:49:25,032 - root - WARNING - tbllalfhldfhd, warning.

Note that if you rerun this without restarting the IPython session it will write duplicate entries to the file since there would now be two file handlers defined


回答 3

请记住,stderr是logging模块的默认流,因此在IPython和Jupyter笔记本中,除非将流配置为stdout,否则可能看不到任何内容:

import logging
import sys

logging.basicConfig(format='%(asctime)s | %(levelname)s : %(message)s',
                     level=logging.INFO, stream=sys.stdout)

logging.info('Hello world!')

Bear in mind that stderr is the default stream for the logging module, so in IPython and Jupyter notebooks you might not see anything unless you configure the stream to stdout:

import logging
import sys

logging.basicConfig(format='%(asctime)s | %(levelname)s : %(message)s',
                     level=logging.INFO, stream=sys.stdout)

logging.info('Hello world!')

回答 4

现在对我有用的(Jupyter,笔记本服务器是:5.4.1,IPython 7.0.1)

import logging
logging.basicConfig()
logger = logging.getLogger('Something')
logger.setLevel(logging.DEBUG)

现在,我可以使用记录器来打印信息,否则,我只会看到默认级别(logging.WARNING)或更高级别的消息。

What worked for me now (Jupyter, notebook server is: 5.4.1, IPython 7.0.1)

import logging
logging.basicConfig()
logger = logging.getLogger('Something')
logger.setLevel(logging.DEBUG)

Now I can use logger to print info, otherwise I would see only message from the default level (logging.WARNING) or above.


回答 5

您可以通过运行配置日志记录 %config Application.log_level="INFO"

有关更多信息,请参见IPython内核选项。

You can configure logging by running %config Application.log_level="INFO"

For more information, see IPython kernel options


回答 6

我为这两个文件都设置了一个记录器,我希望它能显示在笔记本上。事实证明,添加文件处理程序会清除默认的流处理程序。

logger = logging.getLogger()

formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')

# Setup file handler
fhandler  = logging.FileHandler('my.log')
fhandler.setLevel(logging.DEBUG)
fhandler.setFormatter(formatter)

# Configure stream handler for the cells
chandler = logging.StreamHandler()
chandler.setLevel(logging.DEBUG)
chandler.setFormatter(formatter)

# Add both handlers
logger.addHandler(fhandler)
logger.addHandler(chandler)
logger.setLevel(logging.DEBUG)

# Show the handlers
logger.handlers

# Log Something
logger.info("Test info")
logger.debug("Test debug")
logger.error("Test error")

I setup a logger for both file and I wanted it to show up on the notebook. Turns out adding a filehandler clears out the default stream handlder.

logger = logging.getLogger()

formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')

# Setup file handler
fhandler  = logging.FileHandler('my.log')
fhandler.setLevel(logging.DEBUG)
fhandler.setFormatter(formatter)

# Configure stream handler for the cells
chandler = logging.StreamHandler()
chandler.setLevel(logging.DEBUG)
chandler.setFormatter(formatter)

# Add both handlers
logger.addHandler(fhandler)
logger.addHandler(chandler)
logger.setLevel(logging.DEBUG)

# Show the handlers
logger.handlers

# Log Something
logger.info("Test info")
logger.debug("Test debug")
logger.error("Test error")

回答 7

似乎适用于ipython / jupyter早期版本的解决方案不再起作用。

这是适用于ipython 7.9.0的有效解决方案(也已通过jupyter服务器6.0.2测试):

import logging
logger = logging.getLogger()
logger.setLevel(logging.DEBUG)
logging.debug("test message")

DEBUG:root:test message

It seems that solutions that worked for older versions of ipython/jupyter no longer work.

Here is a working solution for ipython 7.9.0 (also tested with jupyter server 6.0.2):

import logging
logger = logging.getLogger()
logger.setLevel(logging.DEBUG)
logging.debug("test message")

DEBUG:root:test message