Python optparse not accepting options

Question

I have written a function that accepts up to 4 options and 2 arguments. The options are -1, -2, -3, and -u. By default, their values are set to true, true, true, and false, respectively, but enabling any of the options causes that value to flip. Problem is, even when I specify, say,

python comm.py -1 -2 -u test test2

and print the option's values, they still show the default values. Below is the relevant portion of my code:

...
...
...
parser.add_option("-1", action="store_false", dest="xcol1", default=True, help="...")
parser.add_option("-2", action="store_false", dest="xcol2", default=True, help="...")
parser.add_option("-3", action="store_false", dest="dups", default=True, help="...")
parser.add_option("-u", action="store_true", dest="donotsort", default=False, help="...")

options, args = parser.parse_args(sys.argv[2:])

xcol1=options.xcol1
xcol2=options.xcol2
dups=options.dups
donotsort=options.donotsort


print "xcol1:"
print xcol1
print "xcol 2:"
print xcol2
print "dups:"
print dups
print "donotsort:"
print donotsort
print args
...
...
...

Executing the aformentioned command with the above code will output:

True

False

True

test, test2

i.e., the default values. It really should be outputting "False, False, True, True, ...), since options 1, 2, and u are enabled. What am I doing wrong? Is it something to do with the parser, because I'm not 100% sure I'm using the parser correctly.

Additionally, when I list the options as -12u instead of -1 -2 -u, it behaves differently - the boolean values are different

Why would it work the way you expected? You did `-12u` instead of `-1 -2 -u` — Navith, Apr 19 '15 at 01:08
Ok, I changed it to -1 -2 -u and now the output is True, False, True, True - however, the first option should be False. Also, I thought spaces in between separate options wasn't necessary — gallardoelise, Apr 19 '15 at 01:11

dantiston · Accepted Answer · 2015-04-19T01:29:12.047

1

Should be

options, args = parser.parse_args()

Also add in:

print options

Results in:

xcol1:
True
xcol 2:
True
dups:
True
donotsort:
False
['test', 'test2']
{'dups': True, 'donotsort': False, 'xcol2': True, 'xcol1': True}

Explanation:

sys.argv is a list, something like [{myScript.py}, {args...}]. Therefore, sys.argv[2:] gets rid of your flags.

Given:

import sys
print sys.argv

Results:

>>> python showArgs.py -12u
>>> ['showArgs.py', '-12u']

Also, according to the official docs, optparse is deprecated in favor of argparse.

edited Apr 19 '15 at 01:29

answered Apr 19 '15 at 01:20

dantiston

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`argparse` is 3.2+ and OP is using 2.x – Navith Apr 20 '15 at 03:05
@Navith argparse is also available in 2.7: https://docs.python.org/2/howto/argparse.html Or, in <2.7 or <3.2 via pip: https://pypi.python.org/pypi/argparsel http://stackoverflow.com/questions/15330175/how-can-i-get-argparse-in-python-2-6 – dantiston Apr 20 '15 at 15:39

Python optparse not accepting options

1 Answers1