如何在python中表示类的新部分？

Question

比如说我上过这样的课：

class Planet(object):
    def _init_(self, id = 0, name="", mass = 0)
    self.id = id
    self.name = name
    self.mass = mass

我能这样写地球吗-

import(whatever)
name=earth
id=1
mass = 5.97219 × 1024 kg

或者行星地球必须以与类相同的方式编写（对不起，我的格式不好，每个代码都合并到一个块中，而不是单独的块）？你知道吗

Answer 1

您需要创建Planet的实例并对其进行初始化：

earth = Planet()
earth.name = "earth"
earth.id = id
earth.mass = 5.97219 × 1024 kg

Answer 2

class Planet(object):
    def _init_(self, id = 0, name="", mass = 0)
        self.id = id
        self.name = name
        self.mass = mass

earth = Planet(id=1,name="Earth",mass=5.97219*1024)

上课太好了！想象一下，你希望你的星球能够做些什么，可能是对其他星球。这个怎么样？你知道吗

class Planet(object):
    def __init__(self,id=0,name="",mass=0,population=0)
        self.id = id
        self.name = name
        self.mass = mass
        self.population = population
    def colonize(self,other,size = 1000):
        if not isinstance(other,Planet):
            raise TypeError("You can only colonize other celestial bodies!")
        if not isinstance(size,int):
            raise TypeError("You need a number of people to colonize with")
        self.population -= size
        other.population += size

mercury = Planet(1, "Mercury")
venus = Planet(2,"Venus")
earth = Planet(3,"Earth",5.97219*1024,7000000000)
mars = Planet(4,"Mars")

>>> earth.population
7000000000
>>> mars.population
0
>>> earth.colonize(mars)
>>> earth.population
6999999000
>>> mars.population
1000