How can I add selected columns to a select statement in sqlalchemy? - sqlalchemy

Question

If I have the following models:
Base = declarative_base()
class Customer(Base):
__tablename__ = 'Customers'
Id = Column(Integer, primary_key=True)
Name = Column(String(255))
class Order(Base):
__tablename__ = 'Orders'
Id = Column(Integer, primary_key=True)
CustomerId = Column(Integer)
Price = Column(Integer)
First, I create a select statement by
stmt1 = select(Customer)
Then, I want to add some info about orders to it, so I create another statement:
stmt1 = select(Customer)
stmt2 = select(func.row_number().over(partition_by=Order.CustomerId, order_by=Order.Price).label("rn"), Order)
stmt2_subq= stmt2.subquery()
stmt3 = stmt1.join(stmt2_subq, Customer.Id == stmt2_subq.c.CustomerId)
The problem is stmt3 dose not contain Order.Price.
How can I add Order.Price to stmt3?
I can do it by:
stmt4 = select(stmt3.subquery(), Order.Price)
But in this way, it will create a stupid select like:
SELECT anon_1.`Id`,
anon_1.`Name`,
`Orders`.`Price`
FROM
(SELECT `Customers`.`Id` AS `Id`,
`Customers`.`Name` AS `Name`
FROM `Customers`
INNER JOIN
(SELECT row_number() OVER (PARTITION BY `Orders`.`CustomerId`
ORDER BY `Orders`.`Price`) AS rn,
`Orders`.`Id` AS `Id`,
`Orders`.`CustomerId` AS `CustomerId`,
`Orders`.`Price` AS `Price`
FROM `Orders`) AS anon_2 ON `Customers`.`Id` = anon_2.`CustomerId`) AS anon_1,
`Orders`
What I want is:
SELECT `Customers`.`Id` AS `Id`,
`Customers`.`Name` AS `Name`,
anon_2.Price
FROM `Customers`
INNER JOIN
(SELECT row_number() OVER (PARTITION BY `Orders`.`CustomerId`
ORDER BY `Orders`.`Price`) AS rn,
`Orders`.`Id` AS `Id`,
`Orders`.`CustomerId` AS `CustomerId`,
`Orders`.`Price` AS `Price`
FROM `Orders`) AS anon_2 ON `Customers`.`Id` = anon_2.`CustomerId`
How can I get this if I already have a very complex stmt1 in my real code and do not want to modify the stmt1's select args?