Question

I’m new to Python and what I have learnt from getopt is that I can pass command line arguments while executing the python script. Now my question is, is there a way to not set the number of arguments that I can pass in the command line?

My code looks something like this:

try:
     opts, args = getopt.getopt(sys.argv[1:],"h:1:2:3:4:",["help=", "1week=","2week=", "3week=", "4week="])
except getopt.GetoptError:
     print 'test.py -1 <week 1> -2 <week 2> -3 <week 3> -4 <week 4>'
     sys.exit(2)
for opt, arg in opts:
     if opt == '-h':
          print 'test.py -1 <week 1> -2 <week 2> -3 <week 3> -4 <week 4>'
          sys.exit()
     elif opt in ("-1", "--1week"):
          week1 = arg
     elif opt in ("-2", "--2week"):
          week2 = arg
     elif opt in ("-3", "--3week"):
          week3 = arg
     elif opt in ("-4", "--4week"):
          week4 = arg

And to run the above code I use
python test.py -1 89 -2 88 -3 87 -4 86. Is there anyway I can modify this where in I don’t have to always give 4 arguments, but also 3? I want it to be flexible where in sometimes I might give 3 arguments or 4.

Answer 1

If your program accepts one or more week numbers:

from argparse import ArgumentParser

parser = ArgumentParser()
parser.add_argument('weeks', nargs='+', type=int, help='weeks numbers')
args = parser.parse_args()
print(args)

Example

$ python your_script.py 1 2 3

Output

Namespace(weeks=[1, 2, 3])

To produce 'weekly_1_2_3' from the above args.weeks:

result = 'weekly_' + '_'.join(map(str, args.weeks))

The result is 'weekly_1_2_3_4' for 1 2 3 4 command line.