pb with callback in the python optparse module

Question

Hi Guys,

I'm playing with Python 2.6 and its optparse module. I would like to convert one of my arguments to a datetime through a callback but it fails.

Here is the code:

def parsedate(option, opt_str, value, parser):
    option.date = datetime.strptime(value, "%Y/%m/%d")

def parse_options(args):
    parser = OptionParser(usage="%prog -l LOGFOLDER [-e]", version="%prog 1.0")
    parser.add_option("-d", "--date", action="callback", callback="parsedate", dest="date")  
    global options
    (options, args) = parser.parse_args(args)
    print options.date.strftime()

if __name__ == "__main__":
        parse_options(sys.argv[1:])

I get an error File: optparse.py in _check_callback "callback not callable". I guess I'm doing something wrong in the way I define my callback but what ? and why ? Can anyone help ?

UPDATE: As I said in my comment, I think the best way to have a datetime in the options of a command line script is by extending optparse as suggested in the python doc

the following class really works fine for that:

from copy import copy
from optparse import Option, OptionValueError
from datetime import datetime

def check_date(option, opt, value):
    try:
        return datetime.strptime(value, "%Y/%m/%d")
    except ValueError:
        raise OptionValueError(
            "option %s: invalid date value: %r. Should have a format like \"YYYY/MM/DD\"" % (opt, value))

class dateOption (Option):
    TYPES = Option.TYPES + ("date",)
    TYPE_CHECKER = copy(Option.TYPE_CHECKER)
    TYPE_CHECKER["date"] = check_date

Anyway, many thanks for the help!

Answer 1

You have parsedate in quotes. It should not be.