Jupyter notebook solves the problem that printing information cannot be viewed after closing the browser

One 、 Problem description

In the browser, we close the model we are training after printing , Open it again and you can see that there is no information output . In addition to handling cache methods , We can use python Of logging Output log .

Two 、 Code writing

import logging
import sys
import datetime

def init_logger(filename, logger_name):
    '''
    @brief:
        initialize logger that redirect info to a file just in case we lost connection to the notebook
    @params:
        filename: to which file should we log all the info
        logger_name: an alias to the logger
    '''

    # get current timestamp
    timestamp = datetime.datetime.utcnow().strftime('%Y%m%d_%H-%M-%S')
    
    logging.basicConfig(
        level=logging.INFO, 
        format='[%(asctime)s] %(name)s {%(filename)s:%(lineno)d} %(levelname)s - %(message)s',
        handlers=[
            logging.FileHandler(filename=filename),
            logging.StreamHandler(sys.stdout)
        ]
    )

    # Test
    logger = logging.getLogger(logger_name)
    logger.info('### Init. Logger {} ###'.format(logger_name))
    return logger

# Initialize
my_logger = init_logger("./ml_notebook.log", "ml_logger")

Print out each time, such as ：

my_logger.info("XXX")

Another example is to record the last cell Time and output of , Print to the log file , For example, in the first cell in ：

%%capture out
%%timeit
a = 1+1

  And then next cell in ：

my_logger.info("capture & timeit: " + out.stdout)

You can know the last cell Running time and content .

Reference resources ：

jupyter notebook How to execute and save the results in the background after closing the browser ? - You know (zhihu.com)

logging — Logging facility for Python — Python 3.10.5 documentation