I am trying to get a rotating log file for a GUI application I am writing with python 3.3.4 and PyQt4. I have the following snippet of code in my main script: import logging import resources logger = logging.getLogger('main.test') def main(): logger.setLevel(logging.DEBUG) fh = RotatingFileHandler(resources.LOG_FILE_PATH, maxBytes=500, backupCount=5) formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s') fh.setFormatter(formatter) logger.addHandler(fh) logger.info('main') I have the maxBytes low so that I can test the rotating is working correctly, which it is not. I am getting the following error whenever the log should be rotated: Traceback (most recent call last): File "C:\Python33\lib\logging\handlers.py", line 73, in emit self.doRollover() File "C:\Python33\lib\logging\handlers.py", line 176, in doRollover self.rotate(self.baseFilename, dfn) File "C:\Python33\lib\logging\handlers.py", line 116, in rotate os.rename(source, dest) PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\\Users\\myuser\\.logtest\\test.log.1' And nothing is logged. Any help is much appreciated. Thank you Continue reading...