updated

Author: PavanMudigonda

46-python-oop/cars.py

@@ -10,7 +10,7 @@
 # DUNDER means double underscore __init__ = constructor method
 
 # create a class
-class Car:
+class Car:   # define class name
     # attributes
     def __init__(self, make, model, year, color):  # constructor method
         self.make = make
@@ -20,7 +20,7 @@ def __init__(self, make, model, year, color):  # constructor method
         self.mileage = 0
         self.for_sale = False
 
-    # define methods
+    # define class methods inside the class
     def drive(self):
         print(f"The {self.make} is driving.")
 

47-class-variables/image.png

@@ -1 +1,26 @@
-# Class Variables
+# Class Variables. = Shared among all instances of a class.
+#                    Defined within the class constructor but outside any methods.
+#                    Allow you to share data among all objects created from the class.
+
+class Student:
+
+    class_year = "2025"     # Class variable
+    number_of_students = 0  # Class variable
+
+    def __init__(self, name, age):  # Constructor method
+        self.name = name  # Instance variable
+        self.age = age    # Instance variable
+        # this is how you would access a class variable inside the class
+        Student.number_of_students += 1  # Increment class variable each time a new student object/instance is created
+
+# Note: You can also use self.number_of_students, but using the class name is preferred for clarity.
+Student1 = Student("SpongeBob", 15)
+Student2 = Student("Patrick", 16)
+Student3 = Student("Squidward", 17)
+Student4 = Student("Sandy", 16)
+
+print(f"{Student1.name} is in the class of {Student1.class_year}.")
+print(f"{Student2.name} is in the class of {Student2.class_year}.")
+print(f"{Student3.name} is in the class of {Student3.class_year}.")
+print(f"{Student4.name} is in the class of {Student4.class_year}.")
+print(f"Total number of students: {Student.number_of_students}")

47-class-variables/main.py

@@ -1 +1,34 @@
-# Inheritance
+# Inheritance  = Allows a class to inherit attributes and methods from another class.
+#            Helps to reuse code and establish a relationship between classes.
+#          The class that is inherited from is called the "parent" or "base" class.
+#          The class that inherits is called the "child" or "derived" class.
+# Example:
+
+# Parent class
+class Animal:
+    # lets start a constructor
+    def __init__(self, name):
+        self.name = name
+        self.is_alive = True
+    def eat(self):
+        return f"{self.name} is eating."
+    def sleep(self):
+        return f"{self.name} is sleeping."
+    
+class Dog(Animal):  # Dog inherits from Animal
+    pass
+
+class Cat(Animal):  # Cat inherits from Animal
+    pass
+
+class Mouse(Animal):  # Mouse inherits from Animal
+    pass
+
+dog = Dog("Scooby")
+cat = Cat("Garfield")
+mouse = Mouse("Jerry")
+print(dog.name)  # Output: Scooby
+print(dog.is_alive) # Output: True
+print(dog.eat())   # Output: Scooby is eating.
+print(cat.sleep()) # Output: Garfield is sleeping.
+