CODEWITHSUNDEEP
pythonoptparseoptionparser
user3388884
user3388884

Reputation: 5098

OptionParser() display choices when --help in Python

I need to create an "interface" to my script such that (runs by crontab):

  1. When --help, terminal will display a list of choices (well formatted, separate by \n)
  2. allow multiple choices input (comma delimited)

e.g. (something like the following)

python feedAnimals.py --help 
...... Choices:
           dog
           cat
           fish

python feedAnimals.py --pets dog,cat,fish

Is there anyway to do this with type="choices"? Or can I use type="string"? I tried to insert \n between choices under the "help" option, but these seems to be neglected at run time.

Must be python 2.4 compatible :(

Upvotes: 1

Views: 1559

Answers (3)

eddy85br
eddy85br

Reputation: 294

Look this related questions, the first with a good "type='choice'" example, and the second with multiple values:

Set a default choice for optionparser when the option is given

Processing multiple values for one single option using getopt/optparse?

You may use something like this or process the arguments "by hand":

from optparse import OptionParser

def get_args():
  usage = "Usage: %prog [options]"

  parser = OptionParser()

  parser.add_option("--pet",
    type = "choice",
    action = 'append',
    choices = ["dog", "cat", "fish"],
    default = [],
    dest = pets,
    help = "Available pets: [dog, cat, fish]"
  )

  (options, args) = parser.parse_args()

  print options, args
  return (options, args)

(opt, args) = get_args()
print opt.pets

Then, run:

python test.py --pet cat --pet dog --pet fish

Upvotes: 1

mortymacs
mortymacs

Reputation: 3736

This is example of how to change usage value. Try it:

from optparse import OptionParser 
string = "Choices:\n\tdog\n\tcat\n\tfish"
parser = OptionParser(usage=string)
(options,args) = parser.parse_args()

You can also change your string to this style:

string = """
    Choices:
        dog
        cat
        fish
"""

Then test it:

$python code.py --help

In will show you this something like this result:

Usage: 
    Choices:
        dog
        cat
        fish


Options:
  -h, --help  show this help message and exit

Upvotes: 1

gkusner
gkusner

Reputation: 1244

Try looking at the documentation for argparse, should do what you need - and help (-h, --help) is built in by default

https://docs.python.org/2/library/argparse.html

Upvotes: 1

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