__init__.py 文件源码

def add_month(start_date, months):
    """ introduces calculation with months """
    new_year = start_date.year + int((start_date.month + months - 1)/12)
    new_month = ((start_date.month + months - 1) % 12) + 1
    new_day = min(start_date.day, monthrange(new_year, new_month)[1])
    new_date = date(new_year, new_month, new_day)
    return new_date