def choose_plural_amount(amount, variants):
    """
    Choose proper case depending on amount, for "N of M items" case

    @param amount: amount of objects
    @type amount: C{int} or C{long}

    @param variants: variants (forms) of object in such form:
        (1 object, 2 objects).
    @type variants: 2-element C{sequence} of C{unicode}
        or C{unicode} (two variants with delimeter ',')

    @return: proper variant
    @rtype: C{unicode}

    @raise L{pytils.err.InputParameterError}: input parameters' check failed
        (amount isn't C{int}, variants isn't C{sequence})
    @raise ValueError: amount is negative
    @raise ValueError: variants' length lesser than 2
    """

    if isinstance(variants, unicode):
        variants = utils.split_values(variants)

    check_length(variants, 2)
    check_positive(amount)
    
    amount_str = str(amount)

    if amount == 1 or (amount_str[-1::] == "1" and amount_str[-2::] != "11"):
        variant = 0
    else:
        variant = 1

    return variants[variant]

def in_words_float(amount, _gender=FEMALE):
    """
    Float in words

    @param amount: float numeral
    @type amount: C{float} or C{Decimal}

    @return: in-words reprsentation of float numeral
    @rtype: C{unicode}

    @raise L{pytils.err.InputParameterError}: input parameters' check failed
        (when amount is not C{float})
    @raise ValueError: when ammount is negative
    """
    utils.check_positive(amount)

    pts = []
    # преобразуем целую часть
    pts.append(sum_string(int(amount), 2,
                          (u"целая", u"целых", u"целых")))
    # теперь то, что после запятой
    remainder = _get_float_remainder(amount)
    signs = len(str(remainder)) - 1
    pts.append(sum_string(int(remainder), 2, FRACTIONS[signs]))

    return u" ".join(pts)

def rubles(amount, zero_for_kopeck=False):
    """
    Get string for money

    @param amount: amount of money
    @type amount: C{int}, C{long}, C{float} or C{Decimal}

    @param zero_for_kopeck: If false, then zero kopecks ignored
    @type zero_for_kopeck: C{bool}

    @return: in-words representation of money's amount
    @rtype: C{unicode}

    @raise L{pytils.err.InputParameterError}: input parameters' check failed
        (amount neither C{int}, no C{float})
    @raise ValueError: amount is negative
    """
    check_positive(amount)

    pts = []
    amount = round(amount, 2)
    pts.append(sum_string(int(amount), 1, (u"рубль", u"рубля", u"рублей")))
    remainder = _get_float_remainder(amount, 2)
    iremainder = int(remainder)

    if iremainder != 0 or zero_for_kopeck:
        # если 3.1, то это 10 копеек, а не одна
        if iremainder < 10 and len(remainder) == 1:
            iremainder *= 10
        pts.append(sum_string(iremainder, 2,
                              (u"копейка", u"копейки", u"копеек")))

    return u" ".join(pts)

def sum_string(amount, gender, items=None):
    """
    Get sum in words

    @param amount: amount of objects
    @type amount: C{integer types}

    @param gender: gender of object (MALE, FEMALE or NEUTER)
    @type gender: C{int}

    @param items: variants of object in three forms:
        for one object, for two objects and for five objects
    @type items: 3-element C{sequence} of C{unicode} or
        just C{unicode} (three variants with delimeter ',')

    @return: in-words representation objects' amount
    @rtype: C{unicode}

    @raise ValueError: items isn't 3-element C{sequence} or C{unicode}
    @raise ValueError: amount bigger than 10**36-1
    @raise ValueError: amount is negative
    """
    if isinstance(items, six.text_type):
        items = split_values(items)
    if items is None:
        items = (u"", u"", u"")

    try:
        one_item, two_items, five_items = items
    except ValueError:
        raise ValueError("Items must be 3-element sequence")

    check_positive(amount)

    if amount == 0:
        return u"ноль %s" % five_items

    into = u''
    tmp_val = amount

    # единицы
    into, tmp_val = _sum_string_fn(into, tmp_val, gender, items)
    names = (
        (FEMALE, (u"тысяча", u"тысячи", u"тысяч")), # тысячи
        (MALE,   (u"миллион", u"миллиона", u"миллионов")), # миллионы
        (MALE,   (u"миллиард", u"миллиарда", u"миллиардов")), # миллиарды
        (MALE,   (u"триллион", u"триллиона", u"триллионов")), # триллионы
        (MALE,   (u"квадриллион", u"квадриллиона", u"квадриллионов")), # квадриллионы
        (MALE,   (u"квинтиллион", u"квинтиллиона", u"квинтиллионов")), # квинтиллион
        (MALE,   (u"секстилион", u"секстилиона", u"секстилионов")), # секстилион
        (MALE,   (u"септиллион", u"септиллиона", u"септиллионов")), # септиллион
        (MALE,   (u"октиллион", u"октиллиона", u"октиллионов")), # октиллион
        (MALE,   (u"нониллион", u"нониллиона", u"нониллионов")), # нониллион
        (MALE,   (u"дециллион", u"дециллиона", u"дециллионов")), # дециллион
    )
    for name in names:
        into, tmp_val = _sum_string_fn(into, tmp_val, *name)
        if tmp_val == 0:
            return into
    raise ValueError("Cannot operand with numbers bigger than 10**36-1")

def in_words(amount, gender=None):
    """
    Numeral in words

    @param amount: numeral
    @type amount: C{int}, C{long} or C{float}

    @param gender: gender (MALE, FEMALE or NEUTER)
    @type gender: C{int}

    @return: in-words reprsentation of numeral
    @rtype: C{unicode}

    raise L{pytils.err.InputParameterError}: input parameters' check failed
        (when amount not C{int} or C{float}, gender is not C{int} (and not None),
         gender isn't in (MALE, FEMALE, NEUTER))
    raise ValueError: when amount is negative
    """
    check_positive(amount)
    
    if gender is None:
        args = (amount,)
    else:
        args = (amount, gender)
    # если целое
    if isinstance(amount, (int, long)):
        return in_words_int(*args)
    # если дробное
    elif isinstance(amount, float):
        return in_words_float(*args)
    # ни float, ни int
    else:
        # до сюда не должно дойти
        raise RuntimeError()

def sum_string(amount, gender, items=None, case=NOMINATIVE):
    """
    Get sum in words

    @param amount: amount of objects
    @type amount: C{integer types}

    @param gender: gender of object (MALE, FEMALE or NEUTER)
    @type gender: C{int}

    @param gender: gender (NOMINATIVE or GENITIVE)
    @type gender: C{int}

    @param items: variants of object in three forms:
        for one object, for two objects and for five objects
    @type items: 3-element C{sequence} of C{unicode} or
        just C{unicode} (three variants with delimeter ',')

    @return: in-words representation objects' amount
    @rtype: C{unicode}

    @raise ValueError: items isn't 3-element C{sequence} or C{unicode}
    @raise ValueError: amount bigger than 10**11
    @raise ValueError: amount is negative
    """
    if isinstance(items, six.text_type):
        items = split_values(items)
    if items is None:
        items = (u"", u"", u"")

    try:
        one_item, two_items, five_items = items
    except ValueError:
        raise ValueError("Items must be 3-element sequence")

    check_positive(amount)

    if amount == 0:
        return u"ноль %s" % five_items

    into = u''
    tmp_val = amount

    # единицы
    into, tmp_val = _sum_string_fn(into, tmp_val, gender, items, case=case)
    # тысячи
    into, tmp_val = _sum_string_fn(into, tmp_val, FEMALE,
                                    (u"тысяча", u"тысячи", u"тысяч"), case=case)
    # миллионы
    into, tmp_val = _sum_string_fn(into, tmp_val, MALE,
                                    (u"миллион", u"миллиона", u"миллионов"), case=case)
    # миллиарды
    into, tmp_val = _sum_string_fn(into, tmp_val, MALE,
                                    (u"миллиард", u"миллиарда", u"миллиардов"), case=case)
    if tmp_val == 0:
        return into
    else:
        raise ValueError("Cannot operand with numbers bigger than 10**11")

def sum_string(amount, gender, items=None):
    """
    Get sum in words

    @param amount: amount of objects
    @type amount: C{int} or C{long}

    @param gender: gender of object (MALE, FEMALE or NEUTER)
    @type gender: C{int}

    @param items: variants of object in three forms:
        for one object, for two objects and for five objects
    @type items: 3-element C{sequence} of C{unicode} or
        just C{unicode} (three variants with delimeter ',')

    @return: in-words representation objects' amount
    @rtype: C{unicode}

    @raise L{pytils.err.InputParameterError}: input parameters' check failed
    @raise ValueError: items isn't 3-element C{sequence} or C{unicode}
    @raise ValueError: amount bigger than 10**11
    @raise ValueError: amount is negative
    """
    if isinstance(items, str):
        items = utils.split_values(items)
    if items is None:
        items = ("", "", "")

    try:
        one_item, two_items, five_items = items
    except ValueError:
        raise ValueError("Items must be 3-element sequence")

    check_positive(amount)

    if amount == 0:
        return "ноль %s" % five_items

    into = ''
    tmp_val = amount

    # единицы
    into, tmp_val = _sum_string_fn(into, tmp_val, gender, items)
    # тысячи
    into, tmp_val = _sum_string_fn(into, tmp_val, FEMALE,
                                    ("тысяча", "тысячи", "тысяч"))
    # миллионы
    into, tmp_val = _sum_string_fn(into, tmp_val, MALE,
                                    ("миллион", "миллиона", "миллионов"))
    # миллиарды
    into, tmp_val = _sum_string_fn(into, tmp_val, MALE,
                                    ("миллиард", "миллиарда", "миллиардов"))
    if tmp_val == 0:
        return into
    else:
        raise ValueError("Cannot operand with numbers bigger than 10**11")

def _get_float_remainder(fvalue, signs=9):
    """
    Get remainder of float, i.e. 2.05 -> '05'

    @param fvalue: input value
    @type fvalue: C{integer types}, C{float} or C{Decimal}

    @param signs: maximum number of signs
    @type signs: C{integer types}

    @return: remainder
    @rtype: C{str}

    @raise ValueError: fvalue is negative
    @raise ValueError: signs overflow
    """
    check_positive(fvalue)
    if isinstance(fvalue, six.integer_types):
        return "0"
    if isinstance(fvalue, Decimal) and fvalue.as_tuple()[2] == 0:
        # Decimal.as_tuple() -> (sign, digit_tuple, exponent)
        # если экспонента "0" -- значит дробной части нет
        return "0"

    signs = min(signs, len(FRACTIONS))

    # нужно remainder в строке, потому что дробные X.0Y
    # будут "ломаться" до X.Y
    if 'e' in str(fvalue).lower():
        remainder = str(Decimal(str(fvalue))).split('.')[1]
    else:
        remainder = str(fvalue).split('.')[1]

    iremainder = int(remainder)
    orig_remainder = remainder
    factor = len(str(remainder)) - signs

    if factor > 0:
        # после запятой цифр больше чем signs, округляем
        iremainder = int(round(iremainder / (10.0**factor)))
    format = "%%0%dd" % min(len(remainder), signs)

    remainder = format % iremainder

    if len(remainder) > signs:
        # при округлении цифр вида 0.998 ругаться
        raise ValueError("Signs overflow: I can't round only fractional part \
                          of %s to fit %s in %d signs" % \
                         (str(fvalue), orig_remainder, signs))

    return remainder

def _get_float_remainder(fvalue, signs=9):
    """
    Get remainder of float, i.e. 2.05 -> '05'

    @param fvalue: input value
    @type fvalue: C{int}, C{long} or C{float}

    @param signs: maximum number of signs
    @type signs: C{int} or C{long}

    @return: remainder
    @rtype: C{str}

    @raise L{pytils.err.InputParameterError}: input parameters' check failed
        (fvalue neither C{int}, no C{float})
    @raise ValueError: fvalue is negative
    @raise ValueError: signs overflow
    """
    check_positive(fvalue)
    if isinstance(fvalue, (int, long)):
        return "0"

    signs = min(signs, len(FRACTIONS))

    # нужно remainder в строке, потому что дробные X.0Y
    # будут "ломаться" до X.Y
    remainder = str(fvalue).split('.')[1]
    iremainder = int(remainder)
    orig_remainder = remainder
    factor = len(str(remainder)) - signs

    if factor > 0:
        # после запятой цифр больше чем signs, округляем
        iremainder = int(round(iremainder / (10.0**factor)))
    format = "%%0%dd" % min(len(remainder), signs)

    remainder = format % iremainder

    if len(remainder) > signs:
        # при округлении цифр вида 0.998 ругаться
        raise ValueError("Signs overflow: I can't round only fractional part \
                          of %s to fit %s in %d signs" % \
                         (str(fvalue), orig_remainder, signs))

    return remainder

def in_words_int(amount, gender=MALE):
    """
    Integer in words

    @param amount: numeral
    @type amount: C{integer types}

    @param gender: gender (MALE, FEMALE or NEUTER)
    @type gender: C{int}

    @return: in-words reprsentation of numeral
    @rtype: C{unicode}

    @raise ValueError: amount is negative
    """
    check_positive(amount)

    return sum_string(amount, gender)

def in_words_int(amount, gender=MALE):
    """
    Integer in words

    @param amount: numeral
    @type amount: C{int} or C{long}

    @param gender: gender (MALE, FEMALE or NEUTER)
    @type gender: C{int}

    @return: in-words reprsentation of numeral
    @rtype: C{unicode}

    @raise L{pytils.err.InputParameterError}: input parameters' check failed
        (when amount is not C{int})
    @raise ValueError: amount is negative
    """
    check_positive(amount)

    return sum_string(amount, gender)

def in_words(amount, gender=None, case=NOMINATIVE):
    """
    Numeral in words

    @param amount: numeral
    @type amount: C{integer types}, C{float} or C{Decimal}

    @param gender: gender (MALE, FEMALE or NEUTER)
    @type gender: C{int}

    @param gender: gender (NOMINATIVE or GENITIVE)
    @type gender: C{int}

    @return: in-words reprsentation of numeral
    @rtype: C{unicode}

    raise ValueError: when amount is negative
    """
    check_positive(amount)
    if isinstance(amount, Decimal) and amount.as_tuple()[2] == 0:
        # если целое,
        # т.е. Decimal.as_tuple -> (sign, digits tuple, exponent), exponent=0
        # то как целое
        amount = int(amount)
    if gender is None:
        args = (amount,)
    else:
        args = (amount, gender)
    # если целое
    if isinstance(amount, six.integer_types):
        return in_words_int(*args, case=case)
    # если дробное
    elif isinstance(amount, (float, Decimal)):
        return in_words_float(*args)
    # ни float, ни int, ни Decimal
    else:
        # до сюда не должно дойти
        raise TypeError(
            "amount should be number type (int, long, float, Decimal), got %s"
            % type(amount))

def in_words(amount, gender=None):
    """
    Numeral in words

    @param amount: numeral
    @type amount: C{int}, C{long}, C{float} or C{Decimal}

    @param gender: gender (MALE, FEMALE or NEUTER)
    @type gender: C{int}

    @return: in-words reprsentation of numeral
    @rtype: C{unicode}

    raise L{pytils.err.InputParameterError}: input parameters' check failed
        (when amount not C{int} or C{float}, gender is not C{int} (and not None),
         gender isn't in (MALE, FEMALE, NEUTER))
    raise ValueError: when amount is negative
    """
    check_positive(amount)
    if isinstance(amount, Decimal) and amount.as_tuple()[2] == 0:
        # если целое,
        # т.е. Decimal.as_tuple -> (sign, digits tuple, exponent), exponent=0
        # то как целое
        amount = int(amount)
    if gender is None:
        args = (amount,)
    else:
        args = (amount, gender)
    # если целое
    if isinstance(amount, (int, long)):
        return in_words_int(*args)
    # если дробное
    elif isinstance(amount, (float, Decimal)):
        return in_words_float(*args)
    # ни float, ни int, ни Decimal
    else:
        # до сюда не должно дойти
        raise RuntimeError()

def choose_plural(amount, variants):
    """
    Choose proper case depending on amount

    @param amount: amount of objects
    @type amount: C{int} or C{long}

    @param variants: variants (forms) of object in such form:
        (1 object, 2 objects, 5 objects).
    @type variants: 3-element C{sequence} of C{unicode}
        or C{unicode} (three variants with delimeter ',')

    @return: proper variant
    @rtype: C{unicode}

    @raise L{pytils.err.InputParameterError}: input parameters' check failed
        (amount isn't C{int}, variants isn't C{sequence})
    @raise ValueError: amount is negative
    @raise ValueError: variants' length lesser than 3
    """
    
    if isinstance(variants, unicode):
        variants = utils.split_values(variants)
    
    check_length(variants, 3)
    check_positive(amount)
    
    if amount % 10 == 1 and amount % 100 != 11:
        variant = 0
    elif amount % 10 >= 2 and amount % 10 <= 4 and \
         (amount % 100 < 10 or amount % 100 >= 20):
        variant = 1
    else:
        variant = 2
    
    return variants[variant]

def distance_of_time_in_words(from_time, accuracy=1, to_time=None):
    """
    Represents distance of time in words

    @param from_time: source time (in seconds from epoch)
    @type from_time: C{int}, C{float} or C{datetime.datetime}

    @param accuracy: level of accuracy (1..3), default=1
    @type accuracy: C{int}

    @param to_time: target time (in seconds from epoch),
        default=None translates to current time
    @type to_time: C{int}, C{float} or C{datetime.datetime}

    @return: distance of time in words
    @rtype: unicode

    @raise ValueError: accuracy is lesser or equal zero
    """
    current = False

    if to_time is None:
        current = True
        to_time = datetime.datetime.now()


    check_positive(accuracy, strict=True)

    if not isinstance(from_time, datetime.datetime):
        from_time = datetime.datetime.fromtimestamp(from_time)

    if not isinstance(to_time, datetime.datetime):
        to_time = datetime.datetime.fromtimestamp(to_time)

    if from_time.tzinfo and not to_time.tzinfo:
        to_time = to_time.replace(tzinfo=from_time.tzinfo)

    dt_delta = to_time - from_time
    difference = dt_delta.days*86400 + dt_delta.seconds

    minutes_orig = int(abs(difference)/60.0)
    hours_orig = int(abs(difference)/3600.0)
    days_orig = int(abs(difference)/86400.0)
    in_future = from_time > to_time

    words = []
    values = []
    alternatives = []

    days = days_orig
    hours = hours_orig - days_orig*24

    words.append(u"%d %s" % (days, numeral.choose_plural(days, DAY_VARIANTS)))
    values.append(days)

    words.append(u"%d %s" % \
                  (hours, numeral.choose_plural(hours, HOUR_VARIANTS)))
    values.append(hours)

    days == 0 and hours == 1 and current and alternatives.append(u"час")

    minutes = minutes_orig - hours_orig*60

    words.append(u"%d %s" % (minutes,
                              numeral.choose_plural(minutes, MINUTE_VARIANTS)))
    values.append(minutes)

    days == 0 and hours == 0 and minutes == 1 and current and \
        alternatives.append(u"минуту")


    # убираем из values и words конечные нули
    while values and not values[-1]:
        values.pop()
        words.pop()
    # убираем из values и words начальные нули
    while values and not values[0]:
        values.pop(0)
        words.pop(0)
    limit = min(accuracy, len(words))
    real_words = words[:limit]
    real_values = values[:limit]
    # снова убираем конечные нули
    while real_values and not real_values[-1]:
        real_values.pop()
        real_words.pop()
        limit -= 1

    real_str = u" ".join(real_words)

    # альтернативные варианты нужны только если в real_words одно значение
    # и, вдобавок, если используется текущее время
    alter_str = limit == 1 and current and alternatives and \
                           alternatives[0]
    _result_str = alter_str or real_str
    result_str = in_future and u"%s %s" % (PREFIX_IN, _result_str) \
                           or u"%s %s" % (_result_str, SUFFIX_AGO)

    # если же прошло менее минуты, то real_words -- пустой, и поэтому
    # нужно брать alternatives[0], а не result_str
#.........这里部分代码省略.........

def _sum_string_fn(into, tmp_val, gender, items=None):
    """
    Make in-words representation of single order

    @param into: in-words representation of lower orders
    @type into: C{unicode}

    @param tmp_val: temporary value without lower orders
    @type tmp_val: C{int} or C{long}

    @param gender: gender (MALE, FEMALE or NEUTER)
    @type gender: C{int}

    @param items: variants of objects
    @type items: 3-element C{sequence} of C{unicode}

    @return: new into and tmp_val
    @rtype: C{tuple}

    @raise L{pytils.err.InputParameterError}: input parameters' check failed
    @raise ValueError: tmp_val is negative
    """
    if items is None:
        items = (u"", u"", u"")
    one_item, two_items, five_items = items
    
    check_positive(tmp_val)

    if tmp_val == 0:
        return into, tmp_val

    words = []

    rest = tmp_val % 1000
    tmp_val = tmp_val / 1000
    if rest == 0:
        # последние три знака нулевые
        if into == u"":
            into = u"%s " % five_items
        return into, tmp_val

    # начинаем подсчет с rest
    end_word = five_items

    # сотни
    words.append(HUNDREDS[rest / 100])

    # десятки
    rest = rest % 100
    rest1 = rest / 10
    # особый случай -- tens=1
    tens = rest1 == 1 and TENS[rest] or TENS[rest1]
    words.append(tens)

    # единицы
    if rest1 < 1 or rest1 > 1:
        amount = rest % 10
        end_word = choose_plural(amount, items)
        words.append(ONES[amount][gender-1])
    words.append(end_word)

    # добавляем то, что уже было
    words.append(into)

    # убираем пустые подстроки
    words = filter(lambda x: len(x) > 0, words)

    # склеиваем и отдаем
    return u" ".join(words).strip(), tmp_val