Is there a way to configure a Python logging formatter via config file to log time as Unix timestamp?

Just add

datefmt = %s

to your corresponding formatter config section or formatter constructor call, e.g.:

[formatter_generic]
format = %(asctime)s %(levelname)-5.5s [%(name)s] %(message)s
datefmt = %s

See also logging.Formatter constructor and strftime(3).

I have just found the following solution:

import logging

class UnixTimeStampFormatter(logging.Formatter):
    def formatTime(self, record, datefmt = None):
        return "{0:.6f}".format(record.created)

def main():
    logChannel = logging.StreamHandler()
    logChannel.setFormatter(UnixTimeStampFormatter("%(asctime)s %(levelname)-5.5s [%(name)s] %(message)s"))
    logging.getLogger().setLevel(logging.DEBUG)
    logging.getLogger().addHandler(logChannel)
    logging.debug('hello');

if __name__ == "__main__":
    main()