Python Program to Split joined consecutive similar characters

Given a String, our task is to write a Python program to split on the occurrence of a non-similar character. 

Input : test_str = ‘ggggffggisssbbbeessssstt’

Output : [‘gggg’, ‘ff’, ‘gg’, ‘i’, ‘sss’, ‘bbb’, ‘ee’, ‘sssss’, ‘tt’]

Explanation : All similar consecutive characters are converted to separate strings.

Input : test_str = ‘ggggffgg’

Output : [‘gggg’, ‘ff’, ‘gg’]

Explanation : All similar consecutive characters are converted to separate strings.

Method #1 : Using join() + list comprehension + groupby()

In this, the characters are grouped on similarity using groupby(), join() is used to reform strings list. List comprehension performs task of iterating constructed groups.

Python3

# Python3 code to demonstrate working of
# Split joined consecutive similar characters
# Using join() + list comprehension + groupby()
from itertools import groupby

# initializing string
test_str = 'ggggffggisssbbbeessssstt'

# printing original string
print("The original string is : " + str(test_str))

# groupby groups the elements, join joining Consecutive groups
res = ["".join(group) for ele, group in groupby(test_str)]

# printing result
print("Consecutive split string is : " + str(res))

Output:

The original string is : ggggffggisssbbbeessssstt

Consecutive split string is : [‘gggg’, ‘ff’, ‘gg’, ‘i’, ‘sss’, ‘bbb’, ‘ee’, ‘sssss’, ‘tt’]

Method #2 : Using finditer() + regex + list comprehension

In this, regex is used to check for consecutive equal sequences. The finditer() performs the task of finding the matching regex in a string.

Python3

# Python3 code to demonstrate working of
# Split joined consecutive similar characters
# Using finditer() + regex + list comprehension
import re

# initializing string
test_str = 'ggggffggisssbbbeessssstt'

# printing original string
print("The original string is : " + str(test_str))

# list comprehension iterates for all the formed groups found by regex
# if consecutive numbers need to search "d" can be used.
res = [iters.group(0) for iters in re.finditer(r"(\D)\1*", test_str)]

# printing result
print("Consecutive split string is : " + str(res))

Output:

The original string is : ggggffggisssbbbeessssstt

Consecutive split string is : [‘gggg’, ‘ff’, ‘gg’, ‘i’, ‘sss’, ‘bbb’, ‘ee’, ‘sssss’, ‘tt’]