Python Programming for Raspberry Pi, Sams Teach Yourself in 24 Hours

self.__inventory = inventory

def get_inventory(self):

return self.__inventory

inventory = property(get_inventory, set_inventory)

def buy_Product(self, amount):

self.__inventory = self.__inventory - amount

def __str__(self):

return '{0} - price: ${1:.2f}, inventory:

{2:d}'.format(self.__description, self.__price,

self.__inventory)

The product.py file incorporates all the attributes and methods for the Product

class into a single module. You can now use your Product class in any of your

Python scripts by simply importing the class from the product.py file.

2. Save the product.py file.


3. Open the text editor again and create the script1403.py file. Here’s the code to
   enter into the file:

Click here to view code image

#!/usr/bin/python3

from product import Product

prod1 = Product('carrot', 1.25, 10)

print(prod1)

print('Buying 4 carrots...')

prod1.buy_Product(4)

print(prod1)

print('Changing the price to $1.50...')

prod1.price = 1.50

print(prod1)

The code first uses the from statement to reference the Product class from the

product.py module file. (Make sure you have the product.py file in the same

folder as the script1403.py file.)

4. Save the script1403.py file in the same folder where you saved the
   product.py file.


5. Run the script1403.py file from the command prompt.
   Here’s what you should see when you run the script1403.py file:

Click here to view code image

pi@raspberrypi ~$ python3 script1403.py

carrot - price: $1.25, inventory: 10

Buying 4 carrots...

carrot - price: $1.25, inventory: 6

Changing the price to $1.50...

carrot - price: $1.50, inventory: 6

pi@raspberrypi ~$

The script uses the Product class that you defined in the product.py file to