# Python – Extract range of Consecutive Similar elements ranges from string list

• Last Updated : 20 Aug, 2022

Given a list, extract range of consecutive similar elements.

Input : test_list = [2, 3, 3, 3, 8, 8]
Output : [(2, 0, 0), (3, 1, 3), (8, 4, 5)]
Explanation : 2 occurs from 0th to 0th index, 3 from 1st to 3rd index.

Input : test_list = [3, 3, 3]
Output : [(3, 0, 3)]
Explanation : 3 from 0th to 3rd index.

Approach: Using loop

This is a brute way to tackle this problem. In this, we loop for each element and get a similar element range. These are traced and appended in list accordingly with elements.

## Python3

 `# Python3 code to demonstrate working of ` `# Consecutive Similar elements ranges` `# Using loop`   `# initializing list` `test_list ``=` `[``2``, ``3``, ``3``, ``3``, ``8``, ``8``, ``6``, ``7``, ``7``]`   `# printing original list` `print``(``"The original list is : "` `+` `str``(test_list))`   `res ``=` `[]` `idx ``=` `0` `while` `idx < (``len``(test_list)):` `    ``strt_pos ``=` `idx` `    ``val ``=` `test_list[idx]` `    `  `    ``# getting last pos.` `    ``while` `(idx < ``len``(test_list) ``and` `test_list[idx] ``=``=` `val): ` `        ``idx ``+``=` `1` `    ``end_pos ``=` `idx ``-` `1` `    `  `    ``# appending in format [ele, strt_pos, end_pos]` `    ``res.append((val, strt_pos, end_pos))`   `# printing result ` `print``(``"Elements with range : "` `+` `str``(res))`

Output:

The original list is : [2, 3, 3, 3, 8, 8, 6, 7, 7] Elements with range : [(2, 0, 0), (3, 1, 3), (8, 4, 5), (6, 6, 6), (7, 7, 8)]

Time Complexity: O(n2)

Space Complexity: O(n)

My Personal Notes arrow_drop_up
Related Articles