Add example dir

Author: rampal-punia

example_1_point_class.py renamed to examples/1_point_class.py

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+from abc import ABC, abstractmethod
+
+
+class Animal(ABC):
+    def speed(self):
+        pass
+
+
+class Lion(Animal):
+    def speed(self):
+        print("The maximum speed: 80km/h")
+
+
+class Cheeta(Animal):
+    def speed(self):
+        print("The maximum speed: 125 km/h")

examples/2_1_animal_class.py

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+class Rectangle:
+    def __init__(self, length, width):
+        self.length = length
+        self.width = width
+
+    def area(self):
+        return self.length * self.width
+
+    def perimeter(self):
+        return 2 * (self.length + self.width)
+
+    def get_detail(self):
+        return f"Length: {self.length}, Width: {self.width}"
+
+
+rect1 = Rectangle(5, 4)
+print(rect1.area())
+print(rect1.perimeter())
+print(rect1.get_detail())

example_2_animal_class.py renamed to examples/2_2_animal_class.py

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+# @CodingMantras
+class Rectangle:
+    # Class level variables, shared by all the instances.
+    num_of_sides = 4
+    num_of_diagonals = 2
+
+    def __init__(self, length, width):
+        # Instance level variables. Different for all the instances.
+        # self.length and self.width are instance variables
+        self.length = length
+        self.width = width
+
+    def area(self):
+        """Instance method to calculate the area of individual instance of rectangle
+        class on the basis of instance variables (self.length and self.width).
+        """
+        return self.length * self.width
+
+    def perimeter(self):
+        """Instance method to calculate the perimeter of individual instance.
+        """
+        return 2 * (self.length + self.width)
+
+    @classmethod
+    def instantiate_square(cls, side):
+        """Using class method as an alternate constructor.
+
+        Args:
+            side (int): side of a square
+
+        Returns:
+            class_instance: Rectangle class instance with both sides equal.
+        """
+        return cls(side, side)
+
+    @classmethod
+    def is_quadrilateral(cls):
+        # Class method to manipulate a class variable
+        return cls.num_of_sides == 4
+
+    @staticmethod
+    def rectangle_formulae():
+        # Static method:
+        # Display information related to a rectangle. But does not manipulate or work-upon
+        # any instance or class variables here.
+        print("Area: length X width")
+        print("Perimeter: 2(length + width)")
+        print("Diagonal: square_root(square_of_length + square_of_width)")
+
+
+# Instantiate an object of the Rectangle class.
+rec1 = Rectangle(5, 4)
+
+# Get attributes.
+print(rec1.length)          # Output: 5
+print(rec1.width)           # Output: 4
+print(rec1.area())          # Output: 20
+print(rec1.perimeter())     # Output: 18
+
+
+# Instantiating a square from the rectangle class.
+# Well first of all this is not advisable to do it here in a
+# Rectangle class. But this is just for understanding classmethods as
+# an alternate constructor.
+sq1 = Rectangle.instantiate_square(4)
+print(sq1.length)
+print(sq1.area())
+print(sq1.perimeter())
+print(Rectangle.is_quadrilateral())
+print(Rectangle.rectangle_formulae())
+
+# Note: - The code represented here is for tutorial and understanding
+# purpose only. Not a production-level code.

examples/3_1_rectangle_class.py

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+from ast import literal_eval
+
+
+class Car:
+    '''A base car class. 
+    Store the values of color, year, price and dimension.
+    Dimention attribute is not necessarily required to instentiate the car class.
+    '''
+    # class attribute... applied to all class instances
+    discount_percentage = 0.1
+
+    def __init__(self, color, year, price, dimension=None):
+        self.color = color
+        self.year = year
+        self.price = price
+
+        if dimension is None:
+            self.dimension = (None, None, None)
+        else:
+            self.dimension = dimension
+        assert isinstance(self.dimension, tuple)
+        assert len(self.dimension) == 3
+
+    def display_details(self):
+        '''Display car details. If not dimention then display none.'''
+        car = {
+            'color': self.color,
+            'year': self.year,
+            'price': self.price,
+            'dimension': self.dimension,
+        }
+        return car
+
+    @property
+    def discount_amount(self):
+        '''An attribute of Car class calculated by a method (using property decorator)
+        A pythonic way of getter.
+        '''
+        return self.price * self.discount_percentage
+
+    @property
+    def length(self):
+        return self.dimension[0]
+
+    @property
+    def width(self):
+        return self.dimension[1]
+
+    @property
+    def height(self):
+        return self.dimension[2]
+
+    def discount_price(self):
+        return self.price - self.discount_amount
+
+    def is_smallcar(self):
+        decider_length = 3800
+        return True if self.length < decider_length else False
+
+    @classmethod
+    def set_discount_percentage(cls, discount_percentage):
+        cls.discount_percentage = discount_percentage
+
+    @classmethod
+    def from_file(cls, file_data):
+        created_classes = []
+        for line in file_data:
+            year, price, dimension, color = int(line[0]), int(
+                line[1]), tuple(literal_eval(line[2])), line[3]
+            created_classes.append(cls(color, year, price, dimension))
+
+        return created_classes
+
+
+class DieselCar(Car):
+    fuel_type = 'Diesel'
+
+    def __init__(self, color, year, price, dimension=None, injector=4):
+        super().__init__(color, year, price, dimension)
+        self.injector = injector
+
+
+class ElectricCar(Car):
+    pass
+
+
+if __name__ == '__main__':
+    dcar_1 = DieselCar('white', 2023, 1500000, (4500, 1200, 1300), 4)
+    # car1 = Car('black', 2022, 1000000, (4500, 1100, 1200))
+    # car2 = Car('grey', 2022, 1100000, (3700, 1000, 1100))
+    # print(car1.discount_percentage)
+    # print(car2.discount_percentage)
+
+    # Car.set_discount_percentage(0.15)
+    # print(car1.discount_percentage)
+
+    # with open('file_data.txt', 'r') as fl:
+    #     lines = fl.readlines()
+    #     lines = [line.rstrip('\n').split("-") for line in lines]
+    #     print(lines)
+    #     created_objects = Car.from_file(lines)
+
+    # for obj in created_objects:
+    #     print(obj.display_details())

example_3_rectangle_class.py renamed to examples/3_2_rectangle_class.py

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+class Point:
+    def __init__(self, x, y):
+        self._x = x
+        self._y = y
+
+    def get_x(self):
+        return self._x
+
+    def set_x(self, value):
+        self._x = value
+
+    def get_y(self):
+        return self._y
+
+    def set_y(self, value):
+        self._y = value
+
+
+class Circle:
+    def __init__(self, radius):
+        self._radius = radius
+
+    def _get_radius(self):
+        print("Get radius")
+        return self._radius
+
+    def _set_radius(self, value):
+        print("Set radius")
+        self._radius = value
+
+    def _del_radius(self):
+        print("Delete radius")
+        del self._radius
+
+    radius = property(
+        _get_radius,
+        _set_radius,
+        _del_radius,
+        "The radius properties of the circle class"
+    )
+
+
+class Circle2:
+    def __init__(self, radius):
+        self._radius = radius
+
+    @property
+    def radius(self):
+        print("Get radius")
+        return self._radius
+
+    @radius.setter
+    def radius(self, value):
+        print("Set radius")
+        self._radius = value
+
+    @radius.deleter
+    def radius(self):
+        print("Delete radius")
+        del self._radius
+
+
+if __name__ == '__main__':
+
+    c = Circle(5)
+    print(c.radius)
+    c.radius = 50
+    print(c.radius)
+    # del c.radius
+    # print(c.radius)
+    print(dir(c))
+
+    p = Point(4, 5)
+    print(p.get_x())
+
+    p.set_x(44)
+    print(p.get_x())