python 根据生日计算年龄

import datetime


def calculate_age(birth_s='20181215'):
    birth_d = datetime.datetime.strptime(birth_s, "%Y%m%d")
    today_d = datetime.datetime.now()
    birth_t = birth_d.replace(year=today_d.year)
    if today_d > birth_t:
        age = today_d.year - birth_d.year
    else:
        age = today_d.year - birth_d.year - 1

    print('出生日期：%s' % birth_d)
    print('今年生日：%s' % birth_t)
    print('今天日期：%s' % today_d)
    print('如果今天日期大于今年生日，今年-出生年=年龄')
    print('如果今天日期不大于今年生日，今年-出生年-1=年龄')
    print('年龄：%s' % age)
    return age


if __name__ == '__main__':
    print(calculate_age('20171216'))

放入sqlalchemy模型定义中，id_Num是身份证号，其中6-14位是出生日期。

    @property
    def age(self):
        if len(self.id_Num) > 14:
            birth_s = self.id_Num[6:14]
            birth_d = datetime.datetime.strptime(birth_s, "%Y%m%d")
            today_d = datetime.datetime.now()
            birth_t = birth_d.replace(year=today_d.year)
            if today_d > birth_t:
                age = today_d.year - birth_d.year
            else:
                age = today_d.year - birth_d.year - 1
        else:
            age = 0
        return age