1. 编程实现计算2023-2-1到2023-3-1相隔多少天？

from datetime import datetime

	start_date_str = "2023-2-1"
	end_date_str = "2023-3-1"
	start_date = datetime.strptime(start_date_str, "%Y-%m-%d")
	end_date = datetime.strptime(end_date_str, "%Y-%m-%d")

	result = end_date-start_date
	print("result=",result,",type=",type(result))
	# 当天也算一天，所以需要加一
	days = result.days+1
	print("days=",days)

2. 请写出房东查询订单和房客查询订单的核心代码？

# 以房东的身份查询订单
# 先查询属于自己的房子有哪些
houses = House.query.filter(House.user_id == user_id).all()
houses_ids = [house.id for house in houses]
# 再查询预订了自己房子的订单
orders = Order.query.filter(Order.house_id.in_(houses_ids)).order_by(Order.create_time.desc()).all()

# 以房客的身份查询订单， 查询自己预订的订单
 orders = Order.query.filter(Order.user_id == user_id).order_by(Order.create_time.desc()).all()