如何添加函数参数以获取当前(默认)、前一周或下周的天数

import datetime

def get_week_days(week):
    if week == "current":
        # 获取当前天数
        current_day = datetime.datetime.now().day
        return current_day
    elif week == "previous":
        # 获取前一周的天数
        previous_week = datetime.datetime.now() - datetime.timedelta(days=7)
        previous_day = previous_week.day
        return previous_day
    elif week == "next":
        # 获取下一周的天数
        next_week = datetime.datetime.now() + datetime.timedelta(days=7)
        next_day = next_week.day
        return next_day
    else:
        return "Invalid week option"

# 示例用法
print(get_week_days("current"))  # 获取当前天数
print(get_week_days("previous"))  # 获取前一周的天数
print(get_week_days("next"))  # 获取下一周的天数