Logging to python file doesn't overwrite file when using the mode='w' argument to FileHandler
Question: I have some code to set up a log in Python 2.7 (using the logging module):

    
    
    import os
    import logging
    logger=logging.getLogger('CopasiTools')
    logger.setLevel(logging.DEBUG)
    log_filename=os.path.join(os.path.dirname(copasi_file),os.path.split(copasi_file)[1][:-4]+'_log.log')
    handler=logging.FileHandler(log_filename,mode='w')
    formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")
    handler.setFormatter(formatter)
    logger.addHandler(handler)
    logger.debug('debugging message')
    

This code works and I am getting the output, however I intend to use this log
to do a lot of debugging so I want to overwrite the log file each time its
run. In the [docs](https://docs.python.org/3/library/logging.handlers.html)
say to use the `mode` keyword argument to the 'FileHandler`. It doesn't
specify precisely *which* mode to use for overwrite file each time but I think
a reasonable assumption would be`mode='w'`. This however doesn't work. Can
anybody tell me why?


Answer: I am not familiar with this to much, and I did not really see anything that
stuck out in google. Have you tried just using:

    
    
        handler=logging.FileHandler(log_filename, 'w')
    

