You do not have path to a log file for some reason (/Users/deon/Documents/PyCharmProjects/Developments/deonproject/log). Make sure that all directories exist (if no, create them) and create an empty debug.log log file (just in case).
What happens is there is some problem with your code happening. Handler catches this error to save it to your log file so that you can analyze it. However, the path to log file it is trying to open does not exist. Thus, exception occures during handling of another exception.