数値のルビ生成

ruby.py

# coding:utf-8

from StringIO import StringIO


RUBY_LIST = (
    (100, u"ひゃく"),
    (10, u"じゅう"),
    (9, u"きゅう"),
    (8, u"はち"),
    (7, u"なな"),
    (6, u"ろく"),
    (5, u"ご"),
    (4, u"よん"),
    (3, u"さん"),
    (2, u"に"),
    (1, u"いち"),
    (0, u"ぜろ"),
)


def number_to_ruby(num, ruby_list=RUBY_LIST):
    u"""
    貪欲法による数値のルビの生成器

    >>> ruby = number_to_ruby(1)
    >>> ruby == u"いち"
    True

    >>> ruby = number_to_ruby(39)
    >>> ruby == u"さんじゅうきゅう"
    True

    >>> ruby = number_to_ruby(74)
    >>> ruby == u"ななじゅうよん"
    True
    """
    ruby_dict = dict(ruby_list)

    out = StringIO()
    if num == 0:
        out.write(ruby_dict[0])
    while num:
        for n, ruby in ruby_dict:
            if num < n:
                continue
            m = num / n
            if m > 1:
                out.write(number_to_ruby(m))
            out.write(ruby)
            num = num % n
            break
    return out.getvalue()


if __name__ == '__main__':
    import doctest
    doctest.testmod()