LH Solution

number_to_word.py

units = ["zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"]
tens = ["", "ten", "twenty", "thirty", "fourty", "fifty", "sixty", "seventy", "eighty", "ninety"]
scales = ["", "thousand", "million", "billion", "trillion"]

def conver_number_to_word(number):
    if number < 20:
        return units[number]
    elif number < 100:
        unit = conver_number_to_word(number % 10)
        if number % 10 == 0:
            return tens[number // 10]
        else:
            return str(tens[number // 10]) + " " + str(unit)

    elif number < 1000:
        unit = conver_number_to_word(number % 100)
        if number % 100 == 0:
            return units[number // 100] + " hundred"
        else:
            return units[number // 100] + " hundred and " + unit

    else:
        words = []
        scale = 0
        while number > 0:
            words.append(conver_number_to_word(number % 1000) + " " + scales[scale])
            number = number // 1000
            scale += 1

        return ' '.join(reversed(words))


if __name__ == "__main__":
    print(conver_number_to_word(11) == "eleven")
    print(conver_number_to_word(12) == "twelve")
    print(conver_number_to_word(7) == "seven")
    print(conver_number_to_word(52) == "fifty two")
    print(conver_number_to_word(10) == "ten")
    print(conver_number_to_word(100) == "one hundred")
    print(conver_number_to_word(300) == "three hundred")
    print(conver_number_to_word(325) == "three hundred and twenty five")
    print(conver_number_to_word(202) == "two hundred and two")
    print(conver_number_to_word(1235) == "one thousand two hundred and thirty five ")
    print(conver_number_to_word(12345) == "twelve thousand three hundred and fourty five ")
    print(conver_number_to_word(123123) == "one hundred and twenty three thousand one hundred and twenty three ")
    print(conver_number_to_word(9123123) == "nine million one hundred and twenty three thousand one hundred and twenty three ")