title: Python logging file handler not using specified handler
body: <p>I am using a logger.conf file included below where I have two loggers three if you count root. OnPremLog is used in normal circumstances and I just recently created TestingLog for handling automated unit testing that requires to run the code not in the normal operational environment. When I implemented this new logger I now have a handler for each. </p>
  
  <p>The issue is when I was running my OnPremCode using that logger as usual, the file handler is now behaving as if it was the testing handler (it is writing instead of appending). I want the test logger to just overwrite the log each time but normal operations I have dozens of scripts that write to the same log and should append. First is my implementation of the logger from a snippet of actual code then the conf file in entirety.</p>
  
  <p>For those that want more background this is running on python 3.7 on windows and the automated build happens on some docker image of linux but that is not the issue being dealt with. </p>
  
  <p>Implementation:</p>
  
  <pre><code>logging.logFileFullPath = cfg.LogsFolder + cfg.onPremLogFile + T_STAMP + '.log'
  logging.config.fileConfig(cfg.ScriptsFolder + cfg.LogConfFile)
  LOGGER = logging.getLogger('OnPremLog')
  </code></pre>
  
  <p>After seeing the similar question and answer to it pointing to case sensitivity I checked and my references are case correct.</p>
  
  <p>Conf File: </p>
  
  <pre><code>[loggers]
  keys=root,OnPremLog,TestingLog
  
  [handlers]
  keys=MainHand,OnPremHand,TestingHand
  
  [formatters]
  keys=MainForm
  
  [logger_root]
  level=NOTSET
  handlers=MainHand
  
  [logger_OnPremLog]
  level=INFO
  handlers=OnPremHand
  qualname=OnPremLog
  propagate=0
  
  [logger_TestingLog]
  level=INFO
  handlers=TestingHand
  qualname=TestingLog
  propagate=0
  
  [handler_MainHand]
  class=StreamHandler
  level=WARNING
  formatter=MainForm
  args=(sys.stdout,)
  
  [handler_OnPremHand]
  class=FileHandler
  level=INFO
  formatter=MainForm
  args=(logFileFullPath, 'a')
  
  [handler_TestingHand]
  class=FileHandler
  level=INFO
  formatter=MainForm
  args=(logFileFullPath, 'w')
  
  [formatter_MainForm]
  format=GACF~%(asctime)s~%(levelname)s~%(filename)s~%(name)s~%(message)s
  datefmt=
  class=logging.Formatter
  </code></pre>