Python argparse question

MTK358 · 12-18-2010, 08:28 PM

How do you implement programs where you can specify an operation as the first argument, and all the other arguments depend on the operation?

Is this possible with Python argparse?

If you don't know what I'm talking about, think of commands like "apt-get install" or "git branch".

kbp · 12-18-2010, 09:50 PM

The logic to interpret the arguments will be part of your script, I usually use getopt though ...

Code:

import getopt

def main():
  try:
    opts, args = getopt.getopt(sys.argv[1:], "s:t:h", ["source=",target=", "help"])
  except getopt.GetoptError, err:
    print str(err)
    usage()
    sys.exit(2)
  for opt, arg in opts:
    if opt in ("-s", "--source"):
      source = arg
    elif opt in ("-t", "--target"):
      target = arg
    elif opt == '-h':
      usage()
      sys.exit()
    else:
      assert False, "Invalid option"

# put arg validation logic here

cheers