code: def gendiff(self, force=False):
          
  
          with DirContext(self.local_settings_dir) as dircontext:
              if not os.path.exists(self.local_settings_diff) or force:
                  with open(self.local_settings_example, 'r') as fp:
                      example_lines = fp.readlines()
                  with open(self.local_settings_file, 'r') as fp:
                      local_settings_lines = fp.readlines()
                  local_settings_example_mtime = time.strftime(
                      self.time_fmt,
                      time.localtime(
                          os.stat(self.local_settings_example).st_mtime)
                  )
  
                  local_settings_mtime = time.strftime(
                      self.time_fmt,
                      time.localtime(os.stat(self.local_settings_file).st_mtime)
                  )
  
                  print('generating "%s"...' % os.path.join(
                      dircontext.curdir,
                      self.local_settings_diff)
                  )
                  with open(self.local_settings_diff, 'w') as fp:
                      for line in difflib.unified_diff(
                          example_lines, local_settings_lines,
                          fromfile=self.local_settings_example,
                          tofile=self.local_settings_file,
                          fromfiledate=local_settings_example_mtime,
                          tofiledate=local_settings_mtime
                      ):
                          fp.write(line)
                  print('\tDONE.')
                  sys.exit(0)
              else:
                  sys.exit(
                      '"%s" already exists.' %
                      os.path.join(dircontext.curdir,
                                   self.local_settings_diff)
                  )
docs: Generate a diff between self.local_settings and the example file.