code: def merge(mer_inputs=MER_INPUTS, mer_output=MER_OUTPUT):
      
      dirname = os.path.dirname(__file__)
      output_file = os.path.join(dirname, DICT_DIRECTORY, mer_output)
      lines = []
      for in_file in MER_INPUTS:
          input_file = os.path.join(dirname, DICT_DIRECTORY, in_file)
          with open(input_file, encoding='utf-8') as f:
              for line in f:
                  lines.append(line)
  
      with open(output_file, 'w', encoding='utf-8') as f:
          for line in lines:
              f.write(line)
docs: merge the phrase files into one file
      :param mer_inputs: the phrase files
      :param mer_output: the output file
      :return: None