如何在python中的函数中传递对象的实例作为参数？

Question

我刚刚开始学习python,我对如何传递一个对象的实例作为一个函数的参数感到困惑,下面是我为练习做的一些代码,基本的想法是有一个车库,这个车库不包含汽车,您可以将车辆添加到车库并查看其详细信息.

class Garage:
    cars = []

    def add_car(self, car):
        cars.append(car)

class Car:
    car_name, car_price, car_colour, car_miles, car_owners = "", "", "", "", ""

    def add_new_car(self, garage, name, price, colour, miles, owners):
        car_name = name
        car_price = price
        car_colour = colour
        car_miles = miles
        car_owners = owners

        garage.add_car(self)

def main(argv=None):    
    your_garage = Garage()

    while True:
        print "Your garage contains %d cars!" % len(your_garage.cars)
        print "1) Add a new car\n2) View your car's\n0) Leave the garage"
        user_input = raw_input("Please pick an option: ")

        if user_input == "1":
            add_car(your_garage)
        elif user_input == "2":
            view_cars(your_garage)
        elif user_input == "0":
            quit()

def add_car(garage):
    name = raw_input("Name: ")
    price = raw_input("Price: ")
    colour = raw_input("Colour: ")
    miles = raw_input("Miles: ")
    owners = raw_input("Owners: ")

    car = Car()
    car.add_new_car(garage, name, price, colour, miles, owners)

def view_cars(garage):
    for x in xrange(len(garage.cars)):
        print garage.cars[x].car_name
        print garage.cars[x].car_price
        print garage.cars[x].car_colour
        print garage.cars[x].car_miles
        print garage.cars[x].car_owners

if __name__ == "__main__":
    main()

我的代码可能是非常错误的,或者可能有一种简单的方法可以做到这一点,我想象的方式是我创建的新实例将被传递到Garage中的add_car()函数,以便它可以被添加到汽车列表中.我怎样才能做到这一点？

Answer 1

也许这个简化的例子会为你指明正确的方向。当前代码中的主要问题之一是，您应该在__init__方法内部（或在对实例操作的其他方法中）设置实例级属性（例如，汽车的颜色或车库的汽车库存），而不是在班级。

class Garage:
    def __init__(self):
        self.cars = []            # Initialize instance attribute here.

    def add_car(self, car):
        self.cars.append(car)

class Car:
    def __init__(self, color):
        self.color = color        # Ditto.

    def __repr__(self):
        return "Car(color={})".format(self.color)

def main():
    g = Garage()
    for c in 'red green blue'.split():
        c = Car(c)
        g.add_car(c)        # Pass the car to the garage's add_car method.
    print g.cars            # [Car(color=red), Car(color=green), Car(color=blue)]

if __name__ == "__main__":
    main()