How to check if a string is in a list, using a function on each item (python3)

Question

I am making a program that is like AI that responds back. I started coding this project but hit a roadblock. I wanted to take a list of words, then check if a given string is inside a list while returning a bool. My code looks something like this...

listofhellos = ['hello', 'hi', 'hey!!!']
if listofhellos.lower() == 'hello': 
# This checks if string 'hello' is in listofhellos
    print('Hey, how are you?')
    # if it is in the list then print out a response

Thank You!

Hi! Though the linked question is related, your request is about checking each item in sequence (using `.lower()`, but maybe any other function), so it's a subtly different request. I edited your title to reflect this. — Joël, Apr 24 '20 at 08:52

score 0 · Accepted Answer · answered Apr 22 '20 at 05:29

0

Here's the Solution:

listofhellos = ['hello', 'hi', 'hey!!!']
check = "Hello"
if check.lower() in listofhellos:
    print('Exists')
else:
    print("Not exists")

answered Apr 22 '20 at 05:29

Stack Kiddy

556
1
4
10

Seems ok, but what if `listofhellos` comes from a user, that puts uppercase character at beginning of each word? – Joël Apr 24 '20 at 08:54

score 0 · Answer 2 · answered Apr 22 '20 at 05:32

0

You can try -

if 'hello' in map(str.lower, ['hello', 'hi', 'Hey!!!']):

or

return 'hello' in map(str.lower, ['hello', 'hi', 'Hey!!!']):```

answered Apr 22 '20 at 05:32

Prethi G

54
3

score -1 · Answer 3 · answered Apr 22 '20 at 05:29

You may want to use any() built-in function in conjonction with the Python 'list comprehension' (well,in fact a generator expression):

if any(item.lower() == 'hello' for item in listofhellos):
    print('hey, how are you?')

This will go over each items of your list in order, test it, and return True at the first item that verifies your test.

How to check if a string is in a list, using a function on each item (python3)

3 Answers3