CODEWITHSUNDEEP
regex
user7128116
user7128116

Reputation:

Regex string with 3 or more vowels

I'm trying to make a regular expression that matches a String with 3 or more vowels.

I've tried this one:

[aeiou]{3,}

But it only works when the vowels are in a sequence. Any tips ?

For example:

  1. Samuel -> valid
  2. Joan -> invalid
  3. Sol Manuel -> valid
  4. Sol -> Invalid

Upvotes: 4

Views: 4776

Answers (5)

Ujjawal
Ujjawal

Reputation: 7

I tried this using help from sniperd's answer:

def multi_vowel_words(text):
   pattern = r"\w+[aeiou]\w*[aeiou]\w*[aeiou]\w+"
   result = re.findall(pattern, text)
   return result

This works even with uppercases.

If you have numbers and underscore in your text, then instead of \w use [a-zA-Z].

Upvotes: 0

sniperd
sniperd

Reputation: 5274

There are several ways to do it and in this case keeping it simple will probably be the most helpful to future devs maintaining that code. That's a fun part about regexes, you can make them very efficient and clever and then very hard for somebody who doesn't do them often to update.

import re

regex = "[aeiou].*[aeiou].*[aeiou]"

mylist = [
"Samuel",  #yes!
"JOAN",  #no!
"Sol Manuel",  #yes!
"",  #no!
]

for text in mylist:
    if re.search(regex, text, re.IGNORECASE):
        print ("Winner!")
    else:
        print ("Nein!")

You could also adjust each part to be [aeiouAEIOU] if you don't have an ignore case flag in your language of choice. Good luck! :)

Upvotes: 5

Mehdi Khademloo
Mehdi Khademloo

Reputation: 2812

just 

(\w*[aeuio]\w*){3,}

or if you want line match

^(.*[aeuio].*){3,}$

Upvotes: 4

Tim Biegeleisen
Tim Biegeleisen

Reputation: 521514

Try this pattern:

^.*[AEIOUaeiou].*[AEIOUaeiou].*[AEIOUaeiou].*$

We could also use a positive lookahead:

^(?=.*[AEIOUaeiou].*[AEIOUaeiou].*[AEIOUaeiou]).*$

Note that due to the possibility of backtracking I would probably prefer using the first (non lookahead) pattern because it should be more efficient.

Upvotes: 0

Rahul
Rahul

Reputation: 2738

This can be achieved using lookaheads like this.

Regex: ^(?=.*[aeiou].*[aeiou].*[aeiou])(?:[a-z] *)+$

Explanation:

  • (?=.*[aeiou].*[aeiou].*[aeiou]) positive lookahead checks for presence of any character followed by vowel three times.

  • (?:[a-zA-Z] *)+ matches your one or more English words separated by spaces.

Regex101 Demo

If Case insensitive Mode is OFF use following regex

Regex: ^(?=.*[aeiouAEIOU].*[aeiouAEIOU].*[aeiouAEIOU])(?:[a-zA-Z] *)+$

Regex101 Demo

Upvotes: 0

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