Time Simplified

# time_convert.py
import datetime


def parse_input(time):
    try:
        data = time.split(':')
        return tuple(data[:3])
    except Exception as e:
        print(e)
        print("Wrong input format")


def generate(date_time):
    minutes, seconds = divmod(date_time.seconds, 60)
    hours, minutes = divmod(minutes, 60)
    return hours, minutes, seconds


def time_converter(time):
    hour, minute, second = parse_input(time)
    total_second = int(hour) * 60 * 60 + int(minute) * 60 + int(second)
    d = datetime.timedelta(seconds=total_second)
    if d.days > 0:
        h, m, s = generate(d)
        result = "{}:{}:{}:{}:".format(d.days, h, m, s)
    elif d.days < 0:
        d = datetime.timedelta(86400) - d
        h, m, s = generate(d)
        result = "-{}:{}:{}:".format(h, m, s)
    else:
        h, m, s = generate(d)
        if h == 0 and m == 0:
            result = "0:"
        else:
            result = "{}:{}:{}:".format(h, m, s)
    print(result)
    return result

--------------------------------------------------
# test_time_convert.py
from time_convert import time_converter

def test():
    assert time_converter('1:2:3:') == '1:2:3:'
    assert time_converter('1:2:90:') == '1:3:30:'
    assert time_converter('1:2:-90:') == '1:0:30:'
    assert time_converter('48:0:0:') == '2:0:0:0:'
    assert time_converter('0:0:0:') == '0:'
    assert time_converter('0:2:-120:') == '0:'
    assert time_converter('1:-300:2:') == '-3:59:58:'


if __name__ == '__main__':
    test()


---------------------------------------------------
$ python test_time_convert.py
1:2:3:
1:3:30:
1:0:30:
2:0:0:0:
0:
0:
-3:59:58: