old_contents: #!/usr/bin/python
  
  import sys
  import subprocess
  
  cmd = sys.argv[1]
  new_args = sys.argv[2:] or []
  subprocess.call(["pitz-%s" % cmd] + new_args)
  
new_contents: #!/usr/bin/python
  
  import sys
  import subprocess
  
  def _help():
      subprocess.call(['pitz-help'])
      sys.exit(1)
  
  if len(sys.argv) < 2:
      _help()
  
  cmd = sys.argv[1]
  new_args = sys.argv[2:] or []
  try:
      subprocess.call(["pitz-%s" % cmd] + new_args)
  except OSError as exc:
      _help()
  
subject: Add at least a minimal exception handling (missing subcommand).