Get Output From the logging Module in IPython Notebook

Question

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

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


        

Answer 1

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

For more information, see IPython kernel options

Answer 2

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.

Answer 3

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")

Answer 4

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

Answer 5

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')

Answer 6

I wanted a simple and straightforward answer to this, with nicely styled output so here's my recommendation

import sys
import logging

logging.basicConfig(
    format='%(asctime)s [%(levelname)s] %(name)s - %(message)s',
    level=logging.INFO,
    datefmt='%Y-%m-%d %H:%M:%S',
    stream=sys.stdout,
)
log = logging.getLogger('notebook')

Then you can use log.info() or any of the other logging levels anywhere in your notebook with output that looks like this

2020-10-28 17:07:08 [INFO] notebook - Hello world
2020-10-28 17:12:22 [INFO] notebook - More info here
2020-10-28 17:12:22 [INFO] notebook - And some more