# -*- coding: utf-8 -*-
"""人民币金额转中文大写。"""
from decimal import Decimal, InvalidOperation, ROUND_HALF_UP


def amount_to_cn(amount):
    """1234.56 -> 壹仟贰佰叁拾肆元伍角陆分"""
    digits = u"零壹贰叁肆伍陆柒捌玖"
    units = [u"", u"拾", u"佰", u"仟"]
    big_units = [u"", u"万", u"亿", u"兆"]

    try:
        amount = Decimal(str(amount)).quantize(Decimal('0.01'), rounding=ROUND_HALF_UP)
        if not amount.is_finite():
            raise ValueError('金额无效')
    except (InvalidOperation, TypeError, ValueError):
        return u"零元整"

    negative = amount < 0
    amount = abs(amount)
    integer_part = int(amount)
    # 避免浮点误差：分位用字符串处理
    fen = int((amount - integer_part) * 100)
    if fen == 100:
        integer_part += 1
        fen = 0

    def int_section(num):
        """0-9999 转中文"""
        s = u""
        zero_flag = False
        str_num = "%04d" % num
        for i, ch in enumerate(str_num):
            d = int(ch)
            pos = 3 - i
            if d == 0:
                zero_flag = True
            else:
                if zero_flag and s:
                    s += digits[0]
                zero_flag = False
                s += digits[d] + units[pos]
        return s

    if integer_part == 0:
        result = u""
    else:
        sections = []
        n = integer_part
        while n > 0:
            sections.append(n % 10000)
            n //= 10000
        parts = []
        for idx, sec in enumerate(sections):
            if sec == 0:
                parts.append(u"")
                continue
            parts.append(int_section(sec) + big_units[idx])
        result = u""
        for idx in range(len(parts) - 1, -1, -1):
            p = parts[idx]
            if not p:
                if result and not result.endswith(digits[0]):
                    result += digits[0]
                continue
            if result and not result.endswith(digits[0]) and idx < len(parts) - 1 and sections[idx] < 1000:
                result += digits[0]
            result += p
        result = result.rstrip(digits[0]) or u"零"

    if fen == 0:
        result += u"元整" if result else u"零元整"
    else:
        jiao = fen // 10
        f = fen % 10
        if result:
            result += u"元"
        if jiao:
            result += digits[jiao] + u"角"
        elif f and result:
            result += digits[0]
        if f:
            result += digits[f] + u"分"
    if negative:
        result = u"负" + result
    return result


if __name__ == "__main__":
    for v in (0, 0.05, 0.5, 1, 10, 100.5, 1234.56, 10000, 1002003, 20340.07,
              100000000, 10500.5):
        print(v, amount_to_cn(v))