Classes and Objects (learnpython.org)

Good lawdy this was a confusing one, but here we go. Python is an object-oriented programming language, and one of the core concepts of object-oriented programming is classes and objects. A class is a blueprint or a template for creating objects, while an object is an instance of a class.

#Basic Class Example
class MyClass:
    variable = "blah"

    def function(self):
        print("This is a message inside the class.")

#Assigning a class template to an object
class MyClass:
    variable = "blah"

    def function(self):
        print("This is a message inside the class.")

myobjectx = MyClass()

In Python, classes are defined using the class keyword, followed by the name of the class, and a colon. The code block that defines the class is then indented below the class definition. The class can contain attributes, which are variables that store data, and methods, which are functions that perform actions.

#Accessing the variable inside of the object "myobjectx"
class MyClass:
    variable = "blah"

    def function(self):
        print("This is a message inside the class.")

myobjectx = MyClass()
myobjectx.variable

#Prining the variable inside
class MyClass:
    variable = "blah"

    def function(self):
        print("This is a message inside the class.")

myobjectx = MyClass()

print(myobjectx.variable)

To create an object from a class, you use the class name followed by parentheses. You can then access the attributes and methods of the object using dot notation.

#Changing the variables inside a duplicate object
class MyClass:
    variable = "blah"

    def function(self):
        print("This is a message inside the class.")

myobjectx = MyClass()
myobjecty = MyClass()

myobjecty.variable = "yackity"

# Then print out both values
print(myobjectx.variable)
print(myobjecty.variable)

#The same process applies to functions
class MyClass:
    variable = "blah"

    def function(self):
        print("This is a message inside the class.")

myobjectx = MyClass()

myobjectx.function()

#The __init__() function
class NumberHolder:

   def __init__(self, number):
       self.number = number

   def returnNumber(self):
       return self.number

var = NumberHolder(7)
print(var.returnNumber()) #Prints '7'

One of the main benefits of using classes and objects is that they allow you to encapsulate data and behavior into a single entity. This makes your code more modular and easier to maintain. It also makes it easier to reuse code, as you can create multiple objects from the same class, each with their own data and behavior.

In addition, classes and objects allow you to model real-world objects and concepts in your code. For example, you could create a class called Car, with attributes like make, model, and year, and methods like start, stop, and accelerate.

Classes and Objects Exercise Solution

#Code Completed
# define the Vehicle class
class Vehicle:
    name = ""
    kind = "car"
    color = ""
    value = 100.00
    def description(self):
        desc_str = "%s is a %s %s worth $%.2f." % (self.name, self.color, self.kind, self.value)
        return desc_str

# your code goes here
car1 = Vehicle()
car1.name = "Fer"
car1.color = "red"
car1.kind = "convertible"
car1.value = 60000.00

car2 = Vehicle()
car2.name = "Jump"
car2.color = "blue"
car2.kind = "van"
car2.value = 10000.00

# test code
print(car1.description())
print(car2.description())

To sum up, classes and objects are a core concept in object-oriented programming, and Python provides powerful tools for creating and using them. By encapsulating data and behavior into classes and objects, you can create modular, reusable, and maintainable code. Whether modeling real-world objects or creating new abstractions, classes and objects are an essential tool for any Python developer.