Format time in Python using pytest

test_format_time.py

"""
TDD solution to:
Input: a bunch of times, minutes and seconds, formatted as a single string like: "12:32 34:01 15:23 9:27 55:22 25:56"
Output: the sum of the times, hours, minutes, and seconds, formatted as a single string like: "2:32:41"
https://github.com/cjdev/interview-preparation
https://coderpad.io/sandbox
"""


import pytest

def sum_times(input_str: str) -> str:
    """Sums the space separated times in the input and formats as a string.
    
    Args:
        input_str: a bunch of times, minutes and seconds, formatted as a single string like: "12:32 34:01 15:23 9:27 55:22 25:56"
    Returns:
        The sum of the times, hours, minutes, and seconds, formatted as a single string like: "2:32:41"
    """
    if not input_str:
        return '0:00:00'
    times = input_str.split(' ')
    tuples = [time.split(":") for time in times]
    sums = [sum(int(x[t]) for x in tuples) for t in range(2)]
    minutes, seconds = divmod(sums[1], 60)
    minutes += sums[0]
    hours, minutes = divmod(minutes, 60)
    return f'{hours}:{minutes:2d}:{seconds:02d}'

def test_example():
    assert sum_times("12:32 34:01 15:23 9:27 55:22 25:56") == "2:32:41"

def test_empty():
    assert sum_times("") == '0:00:00'

def test_short():
    assert sum_times("12:32") == "0:12:32"

def test_zero():
    assert sum_times("12:02") == "0:12:02"

pytest.main()