Append last letter in a string to another string

Question

I am constructing a chatbot that rhymes in Python. Is it possible to identify the last vowel (and all the letters after that vowel) in a random word and then append those letters to another string without having to go through all the possible letters one by one (like in the following example)

lastLetters = ''    # String we want to append the letters to

if user_answer.endswith("a")
    lastLetters.append("a")

else if user_answer.endswith("b")
    lastLetters.append("b")

Like if the word was right we’d want to get ”ight”

Thanks for the answer, will "lastLetters += user_answer[-1]" append the last letter in user_answer to lastLetters and then remove it from user_answer? I am new to programming in general, so I have a hard time understanding everything. — Felix Iversen, Oct 19 '19 at 14:19
So if I want to do the same thing to the second to last letter, would I write [-2] or [0] then? — Felix Iversen, Oct 19 '19 at 14:23

Dani Mesejo · Answer 1 · 2019-10-19T14:53:55.983

0

You need to find the last index of a vowel, for that you could do something like this (a bit fancy):

s = input("Enter the word: ") # You can do this to get user input
last_index = len(s) - next((i for i, e in enumerate(reversed(s), 1) if e in "aeiou"), -1)
result = s[last_index:]
print(result)

Output

ight

An alternative using regex:

import re

s = "right"
last_index = -1
match = re.search("[aeiou][^aeiou]*$", s)
if match:
    last_index = match.start()

result = s[last_index:]
print(result)

The pattern [aeiou][^aeiou]*$ means match a vowel followed by possibly several characters that are not a vowel ([^aeiou] means not a vowel, the sign ^ inside brackets means negation in regex) until the end of the string. So basically match the last vowel. Notice this assumes a string compose only of consonants and vowels.

edited Oct 19 '19 at 14:53

answered Oct 19 '19 at 14:18

Dani Mesejo

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A regex is probably a more straight forward approach… – deceze Oct 19 '19 at 14:20
The vowels are: **a, e, i, o, u, y**... So, add `y`to your code. – codrelphi Oct 19 '19 at 14:29
Thank you for the answer. Is "s" just a random variable name? – Felix Iversen Oct 19 '19 at 14:29
Okay I will add y – Felix Iversen Oct 19 '19 at 14:30
Yes "s" is just a random variable name – Dani Mesejo Oct 19 '19 at 14:30
How would I do it if I didn't know that the word would be "right"/ it could be any word? – Felix Iversen Oct 19 '19 at 14:35
just change `s` to `user_answer` – Dani Mesejo Oct 19 '19 at 14:46
Okay thank you, and one last question. What does the ^ sign stand for? – Felix Iversen Oct 19 '19 at 14:49
@FelixIversen Added explanation of the regex pattern. – Dani Mesejo Oct 19 '19 at 14:54

Append last letter in a string to another string

1 Answers1