Update

Author: sh-navid

README-PYTHON-HOMEWORKS.md

@@ -121,10 +121,13 @@
 - Date, Time, Format
 - Math
 - def, lambda
+- Review concepts
+
+## TP09
+- [OOP](lessons/python/concepts/object-oriented/README.md)
+- [Decorator](lessons/python/concepts/advanced/simple-decorator.py)
+- [NumPy](lessons/python/modules/numpy/README.md)
 - argv, kwargs
-- Inheritance
-- Decorator
-- NumPy
 - ...
 
 

README.md

@@ -109,7 +109,7 @@
 18. Math
 19. [Date, Time](/lessons/python/concepts/date-time/date-time.py)
 14. [Function, Method, Lambda](/lessons/python/concepts/object-oriented/types-of-methods.py)
-20. [OOP](/lessons/python/concepts/object-oriented/object-oriented.py)
+20. [OOP](/lessons/python/concepts/object-oriented/README.md)
     - Class, Object
     - Constructor
     - ToString, Representation

lessons/python/concepts/object-oriented/README.md

@@ -0,0 +1,26 @@
+# OOP
+
+- Each object has a unique identity.
+- Each object can contain several other objects.
+- Each object can have a series of attributes.
+- Every object has a set of behaviors.
+
+- An object is an instance created from a class. The process of making this sample is called instantiation.
+
+## 4 fundamental concepts of object oriented programming
+  - Abstraction
+    - When we talk about "animal", we are not referring to a specific animal. This is an abstract concept.
+    - Abstraction occurs when a programmer hides irrelevant data about an object or class to reduce complexity.
+  - Polymorphism
+    - Ability to take different forms.
+      - [With inheritance and class method](polymorphism-with-inheritance.py)
+      - [With function](polymorphism-with-functions.py)
+  - [Inheritance](oop-inheritance.py)
+    - Is a mechanism that allows one class to inherit the properties of another class, in the same way that a child inherits certain properties from each of its parents.
+  - [Encapsulation](oop-encapsulation.py)
+    - Means "putting one or more items in a physical or logical package." Encapsulation in object-oriented programming limits access to implementation details.
+    - Is implemented by access specifiers. Access level attributes define the scope of class members.
+      - [Access Modifiers](oop-access-modifiers.py)
+        - public
+        - protected
+        - private

lessons/python/concepts/object-oriented/oop-access-modifiers.py

@@ -0,0 +1,58 @@
+class MyClass:
+    name = "PUBLIC"
+    _family = "PROTECTED"
+    __middle = "PRIVATE"
+
+    def get_private_variable(self):
+        return self.__middle
+
+    @property
+    def family(self):
+        return self._family
+
+    @family.setter
+    def family(self, value):
+        self._family = value
+
+
+# ------------------------------------------------------------
+# Public member
+
+print(MyClass.name)
+
+# ------------------------------------------------------------
+# Protected member - Property
+
+print(MyClass._family)  # Accessible - but do not use it like this
+
+cls = MyClass()
+print(cls.family)
+cls.family += "-Changed"
+print(cls.family)
+print(cls._family)  # Accessible - but do not use it like this
+
+# ------------------------------------------------------------
+# Private member
+
+# print(MyClass.__middle) # AttributeError: type object 'MyClass' has no attribute '__middle'
+print(MyClass().get_private_variable())
+
+
+# ------------------------------------------------------------
+class DerivedClass(MyClass):
+    name="PUBLIC2"
+    _family="PROTECTED2"
+    __middle = "New Private Middle Name"
+
+
+cls = MyClass()
+dcls = DerivedClass()
+
+print(cls.name," --- ", dcls.name)
+print(cls._family," --- ", dcls._family)
+print(cls.get_private_variable()," --- ", dcls.get_private_variable()) # __middle in new class is not shadowed the original one
+"""
+PUBLIC  ---  PUBLIC2
+PROTECTED  ---  PROTECTED2
+PRIVATE  ---  PRIVATE
+"""

lessons/python/concepts/object-oriented/oop-encapsulation.py

@@ -0,0 +1,24 @@
+class Counter:
+    __counter = 0  # Private member
+
+    def inc(self):
+        self.__counter += 1
+
+    def dec(self):
+        self.__counter -= 1
+
+    def reset(self):
+        self.__counter = 0
+
+    def __str__(self) -> str:
+        return str(self.__counter)
+
+
+counter1 = Counter()
+print(counter1)
+counter1.inc()
+print(counter1)
+counter1.reset()
+print(counter1)
+
+# print(counter1.__counter) #AttributeError: 'Counter' object has no attribute '__counter'

lessons/python/concepts/object-oriented/oop-inheritance.py

@@ -0,0 +1,5 @@
+class Parent:
+    pass
+
+class Child(Parent):
+    pass

lessons/python/concepts/object-oriented/polymorphism-with-functions.py

@@ -0,0 +1,8 @@
+def rectangle_area(x,y=None):
+    if y is None:
+        return x*x
+    else:
+        return x*y
+
+print(rectangle_area(12))
+print(rectangle_area(12,13))

lessons/python/concepts/object-oriented/polymorphism-with-inheritance.py

@@ -0,0 +1,29 @@
+class Shape:
+    def area(self):
+        return -1
+
+    def __init__(self, *values) -> None:
+        self.value = values
+
+
+class Rectangle(Shape):
+    def area(self):
+        return self.value[0] * self.value[1]
+
+
+class Triangle(Shape):
+    def area(self):
+        return (self.value[0] * self.value[1]) / 2
+
+
+class Square(Shape):
+    def area(self):
+        return self.value[0] * self.value[0]
+
+
+s1 = Rectangle(10, 12)
+s2 = Triangle(10, 12)
+s3 = Square(10)
+
+for shape in [s1, s2, s3]:
+    print(shape.area())