old_contents: #!/usr/bin/env python
  
  
  import os
  import subprocess
  import sys
  
  
  def main(*argv):
      argv = list(argv)
  
      sys.path.insert(0, argv[1])
  
      return(subprocess.check_call([sys.executable, "-m", "unittest"] + argv[2:],
                                   stdin=sys.stdin,
                                   stdout=sys.stdout,
                                   stderr=sys.stderr))
  
  
  if __name__ == "__main__":
      sys.exit(main(*sys.argv))
  
new_contents: #!/usr/bin/env python
  
  
  import subprocess
  import sys
  
  
  def main(*argv):
      argv = list(argv)
  
      sys.path.insert(0, argv[1])
  
      return(subprocess.check_call([sys.executable, "-m", "unittest"] + argv[2:],
                                   stdin=sys.stdin,
                                   stdout=sys.stdout,
                                   stderr=sys.stderr))
  
  
  if __name__ == "__main__":
      sys.exit(main(*sys.argv))
  
subject: Drop `os` as it is an unneeded import.