How to make string check case insensitive?

Question

I\'ve started learning Python recently and as a practise I\'m working on a text-based adventure game. Right now the code is really ineffective as it checks the user responce

Answer 1

if 'power' in choice.lower():

should do (assuming choice is a string). This will be true if choice contains the word power. If you want to check for equality, use == instead of in.

Also, if you want to make sure that you match power only as a whole word (and not as a part of horsepower or powerhouse), then use regular expressions:

import re
if re.search(r'\bpower\b', choice, re.I):

Answer 2

The str type/object has a method specifically intended for caseless comparison.

At the python3 prompt:

>>> help(str)
...
 |  casefold(...)
 |      S.casefold() -> str
 |      
 |      Return a version of S suitable for caseless comparisons.
...

So, if you add .casefold() to the end of any string, it will give you all lowercase.

Examples:

>>> "Spam".casefold()
'spam'
>>> s = "EggS"
>>> s.casefold()
'eggs'
>>> s == "eggs"
False
>>> s.casefold() == "eggs"
True

Answer 3

This if you're doing exact comparison.

if choice.lower() == "power":

Or this, if you're doing substring comparison.

if "power" in choice.lower():

You also have choice.lower().startswith( "power" ) if that interests you.

Answer 4

use str.lower() to convert all entries to lowercase and only check the string against lower case possibilities.