Python: split a string into character pairs

The problem

Given a string, split it into a list of two-character chunks. If a single character remains at the end, fill the missing second slot in that pair with _.

Examples from the kata:

• 'abc' → ['ab', 'c_']
• 'abcdef' → ['ab', 'cd', 'ef']

Approach

Walk the string in steps of 2 — the slice text[i:i+2] does the heavy lifting. At the end, check whether the last element has length 1; if so, append _.

An empty string returns an empty list — nothing to split.

Solution

def solution(text):
    array = [text[i:i+2] for i in range(0, len(text), 2)]
    if array and len(array[-1]) == 1:
        array[-1] += "_"
    return array

Examples

print(solution("abc"))      # ['ab', 'c_']
print(solution("abcdef"))   # ['ab', 'cd', 'ef']
print(solution(""))         # []
print(solution("a"))        # ['a_']

Summary

A slice every 2 characters plus one line for odd lengths — a simple kata that exercises basic string operations in Python.