Python 在单独的文件中从类创建对象
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/23238352/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Create object from class in separate file
提问by Trenera
I have done several tutorials on Python and I know how to define classes, but I don't know how to use them. For example I create the following file(car.py):
我已经做了几个关于 Python 的教程，我知道如何定义类，但我不知道如何使用它们。例如，我创建以下文件(car.py)：
class Car(object):
condition = 'New'
def __init__(self,brand,model,color):
self.brand = brand
self.model = model
self.color = color
def drive(self):
self.condition = 'Used'
Then I create another file (Mercedes.py), where I want to create an object Mercedes from the class Car:
然后我创建另一个文件 (Mercedes.py)，我想在其中从 Car 类创建一个对象 Mercedes：
Mercedes = Car('Mercedes', 'S Class', 'Red')
, but I get an error:
，但我收到一个错误：
NameError: name 'Car' is not defined
If I create an instance (object) in the same file where I created it (car), I have no problems:
如果我在创建它的同一个文件（汽车）中创建一个实例（对象），我没有问题：
class Car(object):
condition = 'New'
def __init__(self,brand,model,color):
self.brand = brand
self.model = model
self.color = color
def drive(self):
self.condition = 'Used'
Mercedes = Car('Mercedes', 'S Class', 'Red')
print (Mercedes.color)
Which prints:
哪个打印：
Red
So the question is: How can I create an object from a class from different file in the same package (folder)?
所以问题是：如何从同一包（文件夹）中不同文件的类创建对象？
采纳答案by sshashank124
In your Mercedes.py, you should import the car.pyfile as follows (as long as the two files are in the same directory):
在您的 中Mercedes.py，您应该car.py按如下方式导入文件（只要两个文件在同一目录中）：
import car
Then you can do:
然后你可以这样做：
Mercedes = car.Car('Mercedes', 'S Class', 'Red') #note the necessary 'car.'
Alternatively, you could do
或者，你可以做
from car import Car
Mercedes = Car('Mercedes', 'S Class', 'Red') #no need of 'car.' anymore
