An exersice problem

number-to-words.py

import sys

DIGITS = ['zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine']
TEENS = ['ten', 'eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen']
TENS = ['ten', 'twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety']


def speek_0(n: int) -> [str]:
    """Auxiliary function."""
    words = []
    if n == 0:
        return [DIGITS[0]]
    assert n < 1_000_000
    if 1000 <= n:
        thousands = n // 1_000
        words += speek_0(thousands) + ["thousand"]
    n %= 1000
    assert n < 1000
    if 100 <= n:
        hundreds = n // 100 % 10
        words += [DIGITS[hundreds], "hundred"]
    n %= 100
    assert n < 100;
    if 10 <= n < 20:
        words += [TEENS[n - 10]]
    else:
        if 20 <= n < 100:
            words += [TENS[n // 10 - 1]]
            n %= 10
        if 0 < n < 10:
            words += [DIGITS[n]]
    return words


def speek_v1(digits: str) -> str:
    """Number to speech using numerals up to thousands."""
    return " ".join(speek_0(int(digits)))


def speek_1(n: [int]) -> [str]:
    # ???
    pass


def speek_v2(digits: str) -> str:
    return " ".join(speek_1(list(digits)))


TESTCASES = {
    '0': "zero",
    '1': "one",
    '10': "ten",
    '15': "fifteen",
    '20': "twenty",
    '35': "thirty five",
    '100': "one hundred",
    '103': "one hundred three",
    '147': "one hundred forty seven",
    '9452': "nine thousand four hundred fifty two",
    '641384': "six hundred forty one thousand three hundred eighty four",
    # '32641384': "thirty two thousand six hundred forty one thousand three hundred eighty four"
}


def test(fn):
    print('-' * 10, "TESTING", fn.__name__)
    for number, words in TESTCASES.items():
        actual = fn(number)
        print(f"{number} -> {words}  :  {actual}")
        sys.stdout.flush()
        if not actual == words:
            print(f" FAILED : actual {actual}, expected {words}")
            return
    print(" OK ")


test(speek_v1)
test(speek_v2)