Pythonic way to perform a large case/switch

Question

I'm pretty sure this is a really fundamental concept in Python, I'd love it if someone could help me understand how to do the following in a pythonic/clean way. I'm really new to coding so I will just show an example. I think it will be obvious what I am trying to do.

for textLine in textLines:
   foo = re.match('[1-100]', thing)
   if foo:
     list = db.GqlQuery("SELECT * FROM Bar").fetch(100)
     if thing == '1':
       item = list[0]
     elif thing == '2':
       item = list[1]
     elif thing == '3':
       item = list[2]
     .
     .
     .
     elif thing == '100':
       item = list[99]

Thanks for the help!

Answer 1

For the specific code you're showing, the pythonic thing would be to replace the entire if-ladder with:

item = list[int(thing)-1]

Of course, it's possible that your real code doesn't lend itself to collapsing like this.

Answer 2

Why not just do this

item = list[int(thing) - 1]

In more complex cases, you should use a dictionary mapping inputs to outputs.