Python – Split String on vowels

Last Updated : 02 Mar, 2023

Given a String, perform split on vowels.

Example:

Input : test_str = ‘GFGaBst’
Output : [‘GFG’, ‘Bst’]
Explanation : a is vowel and split happens on that.

Input : test_str = ‘GFGaBstuforigeeks’
Output : [‘GFG’, ‘Bst’, ‘f’, ‘r’, ‘g’, ‘ks’]
Explanation : a, e, o, u, i are vowels and split happens on that.

Naive approach:

Initialize variable vowels to contain all the vowels.
Initialize an empty list result and a variable temp to an empty string.
Iterate through each character in the input string test_str.
For each character, check if it is a vowel (by checking if it is in the vowels variable).
If the character is a vowel and the temp variable is not empty, append temp to the result list and reset temp to an empty string.
If the character is not a vowel, add it to the temp variable.
After the iteration, if the temp variable is not empty, append it to the result list.
Return the result list.

Python3

def split_on_vowels(test_str):
    vowels = 'aeiouAEIOU'
    result = []
    temp = ""
    for char in test_str:
        if char in vowels:
            if temp != "":
                result.append(temp)
                temp = ""
        else:
            temp += char
    if temp != "":
        result.append(temp)
    return result
 
test_str = 'GFGaBstuforigeeks'
print(split_on_vowels(test_str))

Output

['GFG', 'Bst', 'f', 'r', 'g', 'ks']

Time Complexity: O(N)
Auxiliary Space: O(N)

Method 1 : Using regex() + split()

In this, we use regex split() which accepts multiple characters to perform split, passing list of vowels, performs split operation over string.

Python3

# Python3 code to demonstrate working of 
# Split String on vowels
# Using split() + regex
import re
 
# initializing strings
test_str = 'GFGaBste4oCS'
 
# printing original string
print("The original string is : " + str(test_str))
 
# splitting on vowels 
# constructing vowels list
# and separating using | operator
res = re.split('a|e|i|o|u', test_str)
 
# printing result 
print("The splitted string : " + str(res)) 

Output

The original string is : GFGaBste4oCS
The splitted string : ['GFG', 'Bst', '4', 'CS']

Time Complexity: O(n), where n is the length of the string “test_str”. The “re.split” function splits the string by searching for specified characters (vowels), which takes linear time proportional to the length of the string.
Auxiliary space: O(1), as it uses a constant amount of memory regardless of the size of the input string “test_str”.

Method 2 : Using replace() and split().

First replace all vowels in string with “*” and then split the string by “*” as delimiter

Python3

# Python3 code to demonstrate working of
# Split String on vowels
 
# initializing strings
test_str = 'GFGaBste4oCS'
 
# printing original string
print("The original string is : " + str(test_str))
 
# splitting on vowels
vow="aeiouAEIOU"
for i in test_str:
    if i in vow:
        test_str=test_str.replace(i,"*")
res=test_str.split("*")
 
# printing result
print("The splitted string : " + str(res))

Output

The original string is : GFGaBste4oCS
The splitted string : ['GFG', 'Bst', '4', 'CS']

Time Complexity: O(n)
Auxiliary Space: O(n)

Method #3 : Using replace(),split() and ord() methods

Python3

# Python3 code to demonstrate working of
# Split String on vowels
 
# initializing strings
test_str = 'GFGaBste4oCS'
 
# printing original string
print("The original string is : " + str(test_str))
 
# splitting on vowels
x=[97, 101, 105, 111, 117, 65, 69, 73, 79, 85]
for i in test_str:
    if ord(i) in x:
        test_str=test_str.replace(i,"*")
res=test_str.split('*')
# printing result
print("The splitted string : " + str(res))

Output

The original string is : GFGaBste4oCS
The splitted string : ['GFG', 'Bst', '4', 'CS']

Time Complexity: O(n)
Auxiliary Space: O(n)

Method #4 : Using operator.countOf() method

Python3

import operator as op
 
 
def split_on_vowels(test_str):
    vowels = 'aeiouAEIOU'
    result = []
    temp = ""
    for char in test_str:
        if op.countOf(vowels, char) > 0:
            if temp != "":
                result.append(temp)
                temp = ""
        else:
            temp += char
    if temp != "":
        result.append(temp)
    return result
 
 
test_str = 'GFGaBstuforigeeks'
print(split_on_vowels(test_str))

Output

['GFG', 'Bst', 'f', 'r', 'g', 'ks']

Time Complexity: O(n)
Auxiliary Space: O(n)

Method5# :using the ‘itertools.groupby ‘function from the ‘itertools’ module

Python3

import itertools
 
# Define the string to be split
test_str = 'GFGaBste4oCS'
 
# Define the vowels to split the string on
vowels = 'aeiouAEIOU'
 
# Print the original string
print("The original string is:", test_str)
 
# Use itertools.groupby to group adjacent characters in test_str based on if they are in vowels
res = [list(g) for k, g in itertools.groupby(test_str, key=lambda x: x not in vowels) if k]
 
# Join each group of characters into a string
res = [''.join(substring) for substring in res]
 
# Print the final split string
print("The split string is:", res)
#this code is contributed by Asif_shaik

Output

The original string is: GFGaBste4oCS
The split string is: ['GFG', 'Bst', '4', 'CS']

Time Complexity: O(n)
Auxiliary Space: O(n)

Method #6: Using translate method

Algorithm:

Initialize a string test_str.
Create a translation table that replaces vowels with spaces using the str.maketrans() method.
Apply the translation table to the test_str using the translate() method and store it in a variable named trans_str.
Split the trans_str on spaces and store the result in a list named res.
Print the result.

Python3

# initializing string
test_str = 'GFGaBste4oCS'
 
# create a translation table that replaces vowels with spaces
trans_table = str.maketrans('aeiouAEIOU', ' '*10)
 
# split the string on spaces
res = test_str.translate(trans_table).split()
 
# printing result
print("The splitted string : " + str(res))
#This code is contributed by Vinay Pinjala.

Output

The splitted string : ['GFG', 'Bst', '4', 'CS']

Time complexity: The time complexity of this code is O(n) because the maketrans(), translate() and split() methods take linear time.
Auxiliary Space: The space complexity of this code is O(n) because we are creating a new string and a new list to store the results.