python:将数字转换为单词

Question

我正在尝试编写一个代码，将数字转换为最多 999 万亿的单词。到目前为止，这是我的代码。它最多可以工作到 119，但在那之后事情会变得一团糟。我不能使用追加或枚举。我坚持如何打印更大的数字；我该如何格式化像 978,674,237,105 这样的数字？

NUMBERS = ["zero", "one", "two","three","four","five","six","seven","eight","nine",
               "ten","eleven","twelve","thirteen","fourteen","fiveteen","sixteen",
               "seventeen","eightteen","nineteen"]

TENS = ["", "", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty",
            "ninety"]

HUNNITS = ["","hundred","thousand","million","billion","trillion"]

n = eval(input("What is the number the you want to convert? "))

def convert():
    if n >= 20:
        tens = n // 10
        units = n % 10

        if units != 0:
            result = TENS[tens] + "-" + NUMBERS[units]
        else:
            result = TENS[tens]
    else:
        result = NUMBERS[n]

    print (result)

def convert2():
    if n >=100:
        tens2 = n//100
        units2 = n%100

        if units2 != 0:
            result2 = HUNNITS[tens2] + "-" + TENS[tens2] + "and" + NUMBERS[units2]
        else:
            result2 = HUNNITS[tens2]
    else:
        result2 = HUNNITS[n]

    print(result2)

def main():
    if n >=20 and n< 100:
        x = convert()
    if n >=100:
        y = convert2()

main()

Answer 1

这可以很容易地递归完成:

def as_words(n):
    """Convert an integer n (+ve or -ve) to English words."""
    # lookups
    ones = ['zero', 'one', 'two', 'three', 'four',
            'five', 'six', 'seven', 'eight', 'nine', 
            'ten', 'eleven', 'twelve', 'thirteen', 'fourteen',
            'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen']
    tens = ['zero', 'ten', 'twenty', 'thirty', 'forty',
            'fifty', 'sixty', 'seventy', 'eighty', 'ninety']
    # negative case
    if n < 0:
        return "minus {0}".format(as_words(abs(n)))
    # 1000+
    for order, word in [(10**12, "trillion"), (10**9, "billion"),
                        (10**6, "million"), (10**3, "thousand")]:
        if n >= order:
            return "{0} {1}{2}".format(as_words(n // order), word,
                                       " {0}".format(as_words(n % order))
                                       if n % order else "")
    # 100-999
    if n >= 100:
        if n % 100:
            return "{0} hundred and {1}".format(as_words(n // 100), 
                                                as_words(n % 100))
        else:
            return "{0} hundred".format(as_words(n // 100))
    # 0-99
    if n < 20:
        return ones[n]
    else:
        return "{0}{1}".format(tens[n // 10],
                               "-{0}".format(as_words(n % 10)) 
                               if n % 10 else "")