code: def _get_fn(fn, mode, load):
      '''
      Load a contents, checking that the file was not modified during the read.
      '''
      try:
          mtime_before = os.path.getmtime(fn)
      except OSError:
          mtime_before = None
  
      try:
          with open(fn, mode) as fp:
              item = load(fp)
      except OpenError:
          raise
      else:
          mtime_after = os.path.getmtime(fn)
          if mtime_before in {None, mtime_after}:
              return item
          else:
              raise EnvironmentError('File was edited during read: %s' % fnf _get_fn(fn, mode, load):
      '''
      Load a contents, checking that the file was not modified during the read.
      '''
      try:
          mtime_before = os.path.getmtime(fn)
      except OSError:
          mtime_before = None
  
      try:
          with open(fn, mode) as fp:
              item = load(fp)
      except OpenError:
          raise
      else:
          mtime_after = os.path.getmtime(fn)
          if mtime_before in {None, mtime_after}:
              return item
          else:
              raise EnvironmentError('File was edited during read: %s' % fn)
docs: Load a contents, checking that the file was not modified during the read.