r/dailyprogrammer [2017-06-27] Challenge #321 [Easy] Talking

# talking_clock.py
from sys import argv


def read_input(filepath='input.txt'):
    with open(filepath, 'r') as f:
        return [l.strip() for l in f.readlines()]


def num_to_words(num):
    num = int(num)
    if num > 60:
        raise NotImplementedError('num_to_words is not implemented for non-time numbers')

    lows = {0: 'oh', 1: 'one', 2: 'two', 3: 'three', 4: 'four', 5: 'five', 6: 'six', 7: 'seven',
               8: 'eight', 9: 'nine', 10: 'ten', 11: 'eleven', 12: 'twelve'}
    highs = {2: 'twenty', 3: 'thirty', 4: 'fourty', 5: 'fifty', 6: 'sixty'}

    result = ''
    if num <= 12:
        result = lows[num]
    elif num <= 19:
        prefix = lows[num % 10] if num != 15 else 'fif'
        result = '{}teen'.format(prefix)
    else:
        result = highs[num // 10]
        low = num % 10

        if low != 0:
            result += ' {}'.format(lows[low])

    return result


def hour_to_words(hour_string):
    hour = int(hour_string)
    pm = hour >= 12

    if pm and hour != 12:
        hour = hour - 12
    elif not pm and hour == 0:
        hour = 12

    am_or_pm = 'pm' if pm else 'am'

    return (num_to_words(hour), am_or_pm)


def minutes_to_words(minutes_string):
    minutes = int(minutes_string)
    result = ''

    if minutes > 0:
        oh = 'oh ' if minutes < 10 else ''
        result = '{}{}'.format(oh, num_to_words(minutes))
    return result


def time_to_words(time_string):
    hours, minutes = time_string.strip().split(':')
    hour_string, am_or_pm = hour_to_words(hours)
    minutes_string = minutes_to_words(minutes)

    return ' '.join([hour_string, minutes_string, am_or_pm]).replace('  ', ' ')


if __name__ == '__main__':
    input_time = []
    if len(argv) > 1:
        input_time = read_input(filepath=argv[1])
    else:
        input_time.extend(read_input())

    for t in input_time:
        print('It\'s {}'.format(time_to_words(t)))

# ------------------------------------
# test file
# test_talking_clock.py

import pytest
import talking_clock as T


def test_num_to_words():
    assert T.num_to_words('1') == 'one'
    assert T.num_to_words('11') == 'eleven'
    assert T.num_to_words('15') == 'fifteen'
    assert T.num_to_words('44') == 'fourty four'
    assert T.num_to_words('60') == 'sixty'

    with pytest.raises(NotImplementedError):
        T.num_to_words('69')


def test_time_to_words():
    assert T.time_to_words('11:11') == 'eleven eleven am'
    assert T.time_to_words('12:59') == 'twelve fifty nine pm'
    assert T.time_to_words('13:09') == 'one oh nine pm'
    assert T.time_to_words('00:00') == 'twelve am'