from datetime import date

def end_of_word(word, n):
    w = {'год': ['год', 'года', 'лет'],
         'месяц': ['месяц', 'месяца', 'месяцев'],
         'день': ['день', 'дня', 'дней']}

    if n == 0:
        return
    elif str(n) in ['1', '21', '31']:
        return str(n) + ' ' + w[word][0]
    elif str(n) in ['11', '12', '13', '14']:
        return str(n) + ' ' + w[word][2]
    elif str(n)[-1] in ['2', '3', '4']:
        return str(n) + ' ' + w[word][1]
    else:
        return str(n) + ' ' + w[word][2]

def compare_date(d1, d2):
    delta = (d2 - d1).days
    # если 1я дата больше второй - меняем их местами
    if delta < 0:
        delta = (d1 - d2).days
        d1, d2 = d2, d1
    # если даты совпадают - то выводим сообщение
    elif delta == 0:
        return 'Даты совпадают'

    extra_days = 0
    result = ''
    years = delta // 365

    if d2.year != d1.year:
        for year in range(1, years + 1):
            if (d2.year - year) % 4 == 0 or ((d2.year - year) % 100 == 0 and (d2.year - year) % 400 == 0):
                extra_days += 1  # високосный год

    rest_days = delta % 365 - extra_days
    months = 0
    days = 0

    month_days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    if d2.year % 4 == 0 or (d2.year % 100 == 0 and d2.year % 400 == 0):
        month_days = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

    for i in reversed(range(d2.month)):
        if rest_days - month_days[i - 1] >= 0:
            rest_days -= month_days[i - 1]
            months += 1

    if d2.month <= d1.month:
        for j in reversed(range(d1.month - 1, 12)):
            if rest_days - month_days[j - 1] >= 0:
                rest_days -= month_days[j - 1]
                months += 1

    days = rest_days

    for s in [('год', years), ('месяц', months), ('день', days)]:
        s = end_of_word(*s)
        if s is not None:
            result += s + ', '

    return result[:-2]


d1 = date(2016, 2, 2)
d2 = date.today()
print(compare_date(d1, d2))