Create object from class in separate file

Question

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):

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:

Mercedes = Car('Mercedes', 'S Class', 'Red')

, but I get an error:

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:

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:

Red

So the question is: How can I create an object from a class from different file in the same package (folder)?

Answer 1

In your Mercedes.py, you should import the car.py file as follows (as long as the two files are in the same directory):

import car

Then you can do:

Mercedes = car.Car('Mercedes', 'S Class', 'Red')  #note the necessary 'car.'

Alternatively, you could do

from car import Car

Mercedes = Car('Mercedes', 'S Class', 'Red')      #no need of 'car.' anymore

Answer 2

Simply use the import command in your Mercedes file. There's a good intro about importing in Python in here

Answer 3

Mercedes.py:

from car import Car

This imports the Car class from car.py To use it:

Mercedes=Car('Mercedes', 'S Class', 'Red')