Constructor :
(i) Constructor is the special function that is created. In Python, there is a special function called "init", which act as a constructor.
(ii) It must begin and end with double underscore.
General format of Constructor :
General format of _init_ method (Constructor function)
def _init_(self, [args .... ]):
<statement>
Destructor :
(i) Destructor is also a special method to destory the objects.
(ii) In Python,_del_() method is used as destructor.It is just opposite to constructor.

Good Morning Bindu Madhavan.

In line No.8, del F.display will not come.

Code:
class Sample:
def_init_(self, n1, n2):
            self._n1=nt
            self_n2-n2
def sum(self):
           print ("Class Variable 1:" self_n1)
           print ("Class Variable 2:", self_n2)
S=Sample (5,10)
S.sum()
Output:
Class Variable 1:5
Class Variable 2: 10
Sum: 15

Variables defined inside a class are called as "Class Variable" and functions are called as "Methods. Class variable and methods are together known as members of the class. The class members should be accessed through objects or instance of class. A class can be defined anywhere in a Python program.
Defining classes: In Python, a class is defined by using the keyword class. Every class has a unique name followed by a colon (:).
Syntax for Defining a Class:
class class_name:
statement_1
statement_2
....................
....................
statement_n

class MyStore:
_prod_code= []
_prod_name= []
_ cost_price= []
_prod_quant= []
def getdata(self):
self.p = int(input("Enter no. of products you need to store: "))
for x in range(self.p):
self._prod_code.
append(int(input("Enter Product Code: ")))
self._prod_name.append(str(input("Enter Product Name: ")))
self._ cost_price.append(int(input("Enter Cost price: ")))
def display(self):
print("Stock in Stores")
print(" ---------------------------------- ")
print("Product Code \t Product Name \t Cost Price")
print(" ------------------------------------- ")
for x in range(self.p):
print(self._prod_code[x], "\t\t", self._prod_name[x], "\t\t", self._cos_ price [x])
print(" ---------------------------------")
def print_bill(self):
total_price = 0
for x in range( self.p):
q=int(input("Enter the quantify for the product code %d : "%self._ prod_code [x]))
self._prod_quant.append(q)
total_price = total_price +self._cost_
price[x]*self._prod_quant[x]
print(" Invoice Receipt ")
print(" --------------------------------------")
print("Product Code\t Product Name\t
Cost Price\t Quantity \t Total Amount")
print(" ------------------------------------ ")
for x in range(self.p):
print(self._prod_code[x], "\t\t", self._prod_name[x], "\t\t",
self._cost_price[x], "\t\t", self._prod_quant[x], "\t\t",
self._pro d_ quan t [x] *self._cost_price [x])
print(" -----------------------------------")
print(" Total Amount = ", total_price)

Class String:
def _init_(self):
self.uppercase=()
self.lowercase=()
self.vowels=()
self.consonants=()
self.spaces=()
self.string= " "
def getstr (self):
self.string=str(input("Enter a String: "))
def count_upper(self):
for ch in self.string:
if (ch.isupper()):
self.uppercase+= 1
def count_Iowert(self):
for ch in self.string:
if (ch.islower()):
self.lowercase+= 1
def count_vowels(self):
for ch in self.string:
if (ch in ('A', 'a', 'e', 'E', 'i', 'I', 'o', 'O', 'u', 'U')):
self.vowels+=1
def count_consonants(self):
for ch in self.string:
if (ch not in ('A', 'a', 'e', 'E', 'i', 'I', 'o', 'O', 'u', 'U')):
self.consonants+= 1
def count_space(self):
for ch in self.string:
if (ch==" ''):
self.spaces+= 1
def execute(self):
self.count_upper()
self.count_lower ()
self.count_vowels ()
self.count_consonants()
self.count_space()
def display(self):
print("The given string contains ...")
print("%d Uppercase letters"%self. uppercase)
print("%d Lowercase letters"%self. lowercase)
print("%d Vowels"%self.vowels)
print("%d Consonants"%self.consonants)
print("%d Spaces"%self.spaces)
S = String()
S.getstr()
S.execute()
S.display()
Output:
Enter a string: Welcome To Learn Computer Science
The given string contains...
5 Uppercase letters
24 Lowercase letters
13 vowels
20 consonants
4 Spaces

class Circle:
pi=3.14
def _init_(self.radius):
self.radius=radius
def area(self):
return Circle. pi*(self.radius**2)
def circumference(self):
return 2*Circle.pi*self.radius
r=int(input("Enter Radius: "))
Ce=Circle(r)
print("The Area =",C.area())
print("The Circumference =", Cxircumferencet())

class test;
def check (self, num)
if num> 0:
print (num, "is positive number")
else:
print (num, "is negative number")
n = test ()
x = int (input("Enter the number"))
n. check (x)

class Mystore:
_prod_code = [ ]
_prod_name = [ ]
_cost price = [ ]
_prod quant = [ ]
def getdata(self):
selt.p= int (input ("Enter no. of products you need to store:"))
for x in range (self.p):
self._prod_code. append (int (input ("Enter Product Code:")))
self._prod_name. append (str (input ("Enter Product Name:"))
self._ cost_price. append (int (input ("Enter cost price:"))
def display (self):
print ("stock in stores")
print ("---------------------")
print ("Product Code\t Product name\t cost price")
print ("------------------")
for x in range (self.p):
print (self._prod_code [x], "\t\t", self._prod_name [x], "It \t", self._cost price [x])
print ("------------------------------")
def print_bill (self):
total_price =0
for x in range (self.p):
q= int(input("Enter the quantity for the product code %d:" %self._prod_code [x]))
self. Prod_quant.append (q)
total_price = total_price + self. _cost_price|x]* self._prod_quant [x]
print ("Invoice Receipt")
print ("---------------")
print ("Product Code\t Product Name\t Cost Price\t Quantity\t Total Amount")
print ("----------------")
for x in range (self.p):
print (self._Prod_code [x), "\t \t", self_prod-name[x], "\t \t",
self._cost_price[x], "\t \t", self._prod-quant [x], "\t \t",
self._prod_quant[x]*self._cost price [x])
print ("-------------------")
print ("Total Amount =", total_price")
S=Mystore ()
S.getdata ()
S.display ()
S.print_bill ()
Output:
Enter no. of products you need to store: 5
Enter Product code: 101
Enter Product Name: Notebook
Enter cost price: 25
Enter Product code: 201
Enter Product Name: pencil
Enter cost price: 35
Enter Product code: 301
Enter Product Name: Pen
Enter cost price: 35
Enter Product code: 401
Enter Product Name: Colour Pencils
Enter cost price: 50
Enter Product code: 501
Enter Product Name: Sketches
Enter cost price: 120
Stock in stores

Enter the quantity for the product code 101:10
Enter the quantity for the product code 201:15
Enter the quantity for the product code 301:10
Enter the quantity for the product code 401:20
Enter the quantity for the product code 501:10
Invoice Receipt