Use a block of code only one time

[gontajones]

import getopt
import sys


# parse command line args
def test_tuple(input_value, t):
    possible_opts = ["desert", "ocean"]
    if input_value in possible_opts:
        if t[possible_opts.index(input_value)] > c_value:
            print("CRITICAL - Active: ", t[possible_opts.index(input_value)])
            sys.exit(2)
        elif t[possible_opts.index(input_value)] > w_value:
            print("WARNING - Active:", t[possible_opts.index(input_value)])
            sys.exit(1)
        else:
            print("OK - Active:", t[possible_opts.index(input_value)])
            sys.exit(0)
    else:
        print("Invalid input")


if __name__ == "__main__":

    t = (786, 200)

    try:
        opts, args = getopt.getopt(sys.argv[1:], "i:w:c:")
    except getopt.GetoptError:
        print("Usage: v2.py -i name -w 10 -c 20")
        sys.exit(2)

    for opt, arg in opts:
        if opt == '-i':
            input_value = arg
        elif opt == '-w':
            w_value = int(arg)
        elif opt == '-c':
            c_value = int(arg)

    # validate args
    if len(sys.argv) == 1:
        print("# Usage:\t -w <warn> -c <crit>")
        sys.exit("No argument pass")
    else:
        test_tuple(input_value, t)

But I suggest you use a dictionary, like:

possible_opts = {
        "desert": 786,
        "ocean": 200
}