def leapdays(y1, y2):
    y1 -= 1
    y2 -= 1
    return (y2//4 - y1//4) - (y2//100 - y1//100) + (y2//400 - y1//400)
Django normally warns about maximum key length, but we error on it.
dataset/ETHPy150Open babble/babble/include/jython/Lib/calendar.py/leapdays--crossover with--dataset/ETHPy150Open adamchainz/django-mysql/django_mysql/cache.py/MySQLCache.validate_key