Python - sys.argv and flag identification

Question

when I accept arguments how to check if two are displayed at the same time, without having a complex conditional

i.e.

#!/usr/bin/python
import random, string
import mymodule
import sys

z = ' '.join(sys.argv[2:])
q = ''.join(sys.argv[3:])
a = ''.join(sys.argv[2:])
s = ' '.join(sys.argv[1:])
flags = sys.argv[1:5]

commands = [["-r", "reverse string passed next with no quotes needed."], ["-j", "joins arguments passed into string. no quotes needed."], ["--palindrome", "tests whether arguments passed are palindrome or not. collective."],["--rand","passes random string of 10 digits/letters"]]

try:
    if "-r" in flags:
        if "-j" in flags:
            print mymodule.reverse(q)
        if not "-j" in flags:
            print mymodule.reverse(z)

    if "-j" in flags:
        if not "-r" in flags:
            print a

    if "--palindrome" in flags: mymodule.ispalindrome(z)

    if (not "-r" or not "-j" or not "--palindrome") in flags: mymodule.say(s)

    if "--rand" in flags: print(''.join([random.choice(string.ascii_letters+"123456789") for f in range(10)]))

    if not sys.argv[1]: print mymodule.no_arg_error

    if "--help" in flags: print commands

except: print mymodule.no_arg_error

I just want to say

if "-r" and "-j" in the flags do not have a special order: do something

Answer 1

Also see getopt. It has a slightly more concise syntax and a complete example in the docs.

Answer 2

Sort of

import optparse

p = optparse.OptionParser()
p.add_option('--foo', '-f', default="yadda")
p.add_option('--bar', '-b')
options, arguments = p.parse_args()

# if options.foo and options.bar ...

Answer 3

I recommend using one argparsefor this (or optparseif you are on Python 2.6.x or later).

Without a module, you will do the following:

if "-r" in flags and "-j" in flags:
    do whatever

But I suggest you read the documentation for argparseand find out how to use it. You will be happy you did.