old_contents: #!/usr/bin/env python3
  
  from unittest import TestLoader, TextTestRunner
  from sys import argv, exit
  
  if __name__ == "__main__":
      suite = TestLoader().discover('tests', pattern = "test_*.py")
      v = 1
      if len(argv) > 1:
          if argv[1] == 'verbose':
              v = 2
          elif argv[1] == 'quiet':
              v = 0
      ret = TextTestRunner(verbosity=v).run(suite)
      exit(not ret.wasSuccessful())
  
new_contents: #!/usr/bin/env python3
  
  from unittest import TestLoader, TextTestRunner
  from sys import argv, exit
  
  if __name__ == "__main__":
      suite = TestLoader().discover('tests', pattern="test_*.py")
      v = 1
      if len(argv) > 1:
          if argv[1] == 'verbose':
              v = 2
          elif argv[1] == 'quiet':
              v = 0
      ret = TextTestRunner(verbosity=v).run(suite)
      exit(not ret.wasSuccessful())
  
subject: テスト実行スクリプトが flake8 に反しているので修正