I'm coming from Tcl-world ...

[geek]

> 2.) A 'switch'-thing: like a big if-elif-elif-elif-...-else but
> which evaluates its expression only once ... and then does all the
> comparisons.

I'm one of those weirdos that would use a dictionary for this.  Here's
a very poor example:

#!/usr/bin/env python

import sys

def yes():
    print 'yes'
    return

def no():
    print 'no'
    return

options = {'-y': yes,
           '-n': no,
           }

for o in sys.argv[1:]:
    try:
        options[o]()
    except:
        print 'Unknown command line arguement'