Log all uncaught exceptions to file with sys.excepthook

logfile.py

import os
import logging
import sys
import time
import traceback

from mypackage import __version__


def _exception_handler(error_type, error_value, error_traceback):
    """Log all uncaught exceptions at runtime with sys.excepthook"""
    log = logging.getLogger(__name__)
    log.exception("Uncaught exception {} {}".format(
        str(error_type), str(error_value)))
    tb = traceback.format_exception(
        error_type, error_value, error_traceback)
    traceback_string = ''
    for ln in tb:
        traceback_string += ln
    log.exception(traceback_string)


def begin_log_file(settings=None):
    """Initialize logging and begin writing log file.

    Parameters
    ----------
    settings : dictionary of user input settings, optional.

    Returns
    -------
    log_filename : str
        Filepath to output log text file location.
    """
    timestamp = time.strftime('%d-%b-%Y_%H-%M%p', time.localtime())
    log_filename = os.path.join(os.path.abspath(os.path.dirname(__file__)),
                                '..', 'logs', 'logging.conf')
    if os.path.exists(log_filename):
        os.remove(log_filename)
    sys.excepthook = _exception_handler
    logging.basicConfig(
        format="%(asctime)s %(message)s",
        level=logging.INFO,
        handlers=[
            logging.FileHandler("{}".format(log_filename)),
            logging.StreamHandler()
        ])
    log = logging.getLogger(__name__)
    # Log user input arguments
    log.info("Wersion {}".format(__version__))
    log.info("{}".format(timestamp))
    if settings:
        log.info("========== USER CONFIG SETTINGS ==========")
        for key, val in settings.items():
            log.info("{}: {}".format(key, val))
        log.info("=========== END OF USER INPUT ============")
    return log_filename