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class Tr:

def_init_(self, a, b, c):

self.a = float(a)

self.b = float(b)

self.c = float(c)

def area(self):

s = (self.a + self.b + self.c)/2

return((s*(s-self.a) * (s-self.b) * (s-self.c) ** 0.5)

a = input(“Enter side 1:”)

b = input(“Enter side2:”)

c = input(“Enter side3:”)

ans=Tr(a,b,c)

print(ans.area( ))

Output:

Enter side 1 : 3

Enter side 2 : 4

Enter side 3 : 5

6.0

Answer is (b) public

All the string variables are of object of class strings

(c) class class_name:

Once a class is created, next you should create an object or instance of that class. The process of creating object is called as “Class Instantiation”. 

Syntax:

object_name = class_name( )

In Python, there is a special function called “init” which act as a Constructor. It must begin and end with double underscore. This function will act as an ordinary function;

General format of init method (Constructor function) def_init_(self.[args …………….]):

<statements>

(b) double underscore

(d) all of these

The first argument of the class method is self

class is defined by the keyword class

(c) Classes and Objects

The statements defined inside the class must be properly indented. True

Classes and Objects are the key features of Object Oriented Programming. Class is the main building block in Python. Object is a collection of data and function that act on those data. Class is a template for the object. According to the concept of Object Oriented Programming, objects are also called as instances of a class or class variable

class stud:

def_init_(self):

self.name= ” ”

self.m1=0

self.m2=0

self.tot=0

def gdata(self):

self.name = input(“Enter your name”)

self.m1 = int(input(“Enter marks 1”))

self.m2 = int(input(“Enter marks2”))

self, tot = self.m1+self.m2

def disp(self):

print(self.name)

print(self.m1)

print(self.m2)

print(self.tot)

mlist = [ ]

st = stud( )

st.gdata( )

mlist. append(st)

for x in mlist:

x.disp( )

Output:

Enter your name Ram

Enter marks 1 100

Enter marks2 100

Ram 100 100 200

(c) destructor

Destructor is also a special method gets executed automatically when an object exit from the scope. It is just opposite to constructor. In Python, _del_( ) method is used as destructor.

In Python, a class is defined by using the keyword class. Every class has a unique name followed by a colon ( : ).

Syntax:

class class_name:

statement_1

statement_2

…………………

…………………

statement_n

Where, statement in a class definition may be a variable declaration, decision control, loop or even a function definition. 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.

Example:

Program to define a class

class Sample:

x, y = 10, 20 # class variables

In the above code, name of the class is Sample and it has two variables x and y having the initial value 10 and 20 respectively. To access the values defined inside the class, you need an object or instance of the class.

Answer (d) _init_( )

Functions defined inside a class Methods

_del_( ) is used as destructor

class variables and methods are called as members of the class

(d) Instantiation

(c) constructor function can be defined with or without argument

General format of init method (Constructor function) 

def_init_(self.[args ……….]):

<statements>

To define destructor

 _del_ ( ) method is used.

class Sample:

def_init_(self,n1,n2):

self._n1=n1

self._n2=n2

def display(self):

print(“class variable 1:” , self._n1)

print(“class variable 2:” , self._n2)

print(“sum self._n1 + self._n2)

s = sample(10, 20)

s.display( )

Output:

class variable 1 : 10

class variable 2 : 20

sum : 30

(a) 1-(iv) 2-(iii) 3-(i) 4-(ii)

Class members are accessed through . operator

_num is the private class variable

A private class variable is prefixed with -

All integer variables used in python program is an object of class int

(a) constructor

class Greeting:

def_init_(self, name):

self._name = name

def display(self):

print(“Good Morning “ , self._name) 

obj=Greeting(‘Bindu Madhavan’)

obj.display( )

Output:

Bindu Madhavan Good Morning

class Sample:

_num=10

def disp(self):

print(self._num) 

S=Sample( )

S.disp( )

print(S._num)

Output:

Error: Sample has no attribute S._num

10

output :

(b) Tamil

Output

Fruit 1 = Apple, Fruit 2 = Mango

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

The class method must have the first argument named as self. No need to pass a value for this argument when we call the method. Python provides its value automatically. Even if – a method takes no arguments, it should be defined with the first argument called self. If a method is defined to accept only one argument it will take it as two arguments ie. self and the defined argument.

private variables can be accessed only within the class

objects are also called as instances of a class or class variable.

class Sample:

def_init_(self, num):

print(“Constructor of class Sample…”)

self.num=num

print(“The value is num)

S=Sample(10)

Constructor of class sample…

The value is: 10

public variables can be accessed anywhere in the program using dot operator

class Dist:

def_init_(self):

self, dist 1=0

self.dist 2=0

def read(self):

self.dist 1=int(input(“Enter distance 1”))

self.dist 2=int(input(“Enter distance 2”))

def disp(self):

print(“distance 1” , self.dist 1)

print(“distance 2” , self.dist 2)

def add(self):

print(“Total distances” , self.dist 1+self.dist 2)

def sub(self):

print(“Subtracted distance” , self.dist 1-self.dist 2) 

d=Dist( )

choi = “y”

while(choi == “y”):

print(” 1. accept \n 2. Display \n 3. Total \n 4. Subtract”)

ch = int(input(“Enter your choice”))

if(ch==l):

d.read( )

elif(ch==2):

d.disp( )

elif(ch==3):

d.add( )

elif(ch==4):

d.sub( )

else: 

print(“Invalid Input…”)

choi = input(“Do you want to continue”)

Output:

1. Accept

2. Display

3. Add

4. Subtract

Enter your choice : 3

Enter distance 1 : 100

Enter distance 2 : 75

Do you want to continue .. y

1. Accept

2. Display

3. Add

4. Subtract

Enter your choice : 3

Total distances : 175

Do you want to continue .. y

1. Accept

2. Display

3. Add

4. Subtract

Enter your choice : 2

Enter distance 1 : 100

Enter distance 2 : 75

Do you want to continue .. y

1. Accept

2. Display

3. Add

4. Sub

Enter your choice : 4

Subtracted distance : 25

Do you want to continue .. N

class Library:

def_init_(self):

self.bookname= ””

self.author= ””

def getdata(self):

self.bookname = input(“Enter Name of the Book: “) 

self.author = input(“Enter Author of the Book: “)

def display(self):

print(“Name of the Book: “ ,self.bookname)

print(” Author of the Book: “ ,self.author)

print(“\n”)

book=[ ] #empty list

ch = ‘y’

while(ch= = ’y’):

print(“1. Add New Book \n 2.Display Books”)

resp = int(input(“Enter your choice :”))

if(resp= =1):

L=Library( )

L.getdata( )

book.append(L)

elif(resp= =2):

for x in book:

x.display( ) 

else:

print(“Invalid input….”)

ch = input(“Do you want continue….”)

Output:

1. Add New Book

2. Display Books

Enter your choice : 1

Enter Name of the Book: Programming in C++ 

Enter Author of the Book: K. Kannan

Do you want continue….y

1. Add New Book

2. Display Books

Enter your choice : 1

Enter Name of the Book: Learn Python

Enter Author of the Book: V.G.Ramakrishnan

Do you want continue….y

1. Add New Book

2. Display Books

Enter your choice : 1

Enter Name of the Book: Advanced Python

Enter Author of the Book: Dr. Vidhya

Do you want continue….y

1. Add New Book

2. Display Books Enter your choice : 1

Enter Name of the Book: Working with OpenOffice 

Enter Author of the Book: N.V.Gowrisankar

Do you want continue….y

1. Add New Book

2. Display Books

Enter your choice : 1

Enter Name of the Book: Data Structure

Enter Author of the Book: K.Lenin

Do you want continue….y

1. Add New Book

2. Display Books

Enter your choice : 1

Enter Name of the Book: An Introduction to Database System

Enter Author of the Book: R.Sreenivasan

Do you want continue….y

1. Add New Book

2. Display Books

Enter your choice : 2

Enter Name of the Book: Programming in C++ 

Enter Author of the Book: K. Kannan

Name of the Book: Learn Python

Author of the Book: V.G.Ramakrishnan

Name of the Book: Advanced Python

Author of the Book: Dr. Vidhya

Name of the Book: Working with OpenOffice 

Author of the Book: N.V.Gowrisankar

Name of the Book: Data Structure

Author of the Book: K.Lenin

Name of the Book: An Introduction to Database System

Author of the Book: R.Sreenivasan

Do you want continue….n

Correct option is (c) Revenue

Correct option is (a) one would increase, another would decrease.

Correct option is (a) increase in one asset – decrease in another asset.

Mahatma Gandhi organised the Champaran Satyagraha in order to voice against the oppressive indigo plantation system.

(i) Salt was something consumed by the rich and the poor alike and was one of the most essential food items. 

(ii) The tax on salt and the government monopoly over its production revealed the most oppressive face of the British. 

(iii) Mahatma thought that an ordinary thing like salt could give the movement a grand success which would ultimately dethrone the foreign rule.

They demanded relaxation in revenue collection.

The term Cold War was used by George Orwell in the context of bitter relations between the countries in modern international politics.

Mahatma Gandhi found in ‘salt’ a powerful symbol that could unite the nation. 

On 31 January 1930, he sent a letter to the Viceroy Irwin, stating eleven demands. The most important demand was to abolish the salt tax. 

Salt is consumed by all sections of the society, by the rich and the poor alike. 

It is one of the most essential items of food. 

Mahatma Gandhi declared that tax on salt and government monopoly over its production was the most oppressive step taken by the British government. 

Mahatma Gandhi choose salt because all sections of the society could identify with it and everyone could be brought into a united struggle.