CBSE IP Chapter 3

• Python is an open-source, high level, interpreter based language that can be used for a multitude of  scientific and non-scientific computing purposes.

• Comments are non-executable statements in a  program.

• An identifier is a user defined name given to a variable or a constant in a program.

• Process of identifying and removing errors from a computer program is called debugging.

• Trying to use a variable that has not been assigned a value gives an error.

• There are several data types in Python — integer, boolean, float, complex, string, list, tuple, sets, None and dictionary. 

• Operators are constructs that manipulate the value of operands. Operators may be unary or binary. 

• An expression is a combination of values, variables, and operators.

• Python has input() function for taking user input.

• Python has print() function to output data to a standard output device.

• The if statement is used for decision making.

• Looping allows sections of code to be executed repeatedly under some condition. 

• for statement can be used to iterate over a range of values or a sequence. 

• The statements within the body of for loop are executed till the range of values is exhausted.

Q1 Which of the following identifier names are invalid and why?    

a) Serial_no. - Valid Identifier Name

b) 1st_Room - InValid Identifier Name, Identifier Name cannot start with Number

c) Hundred$ - InValid Identifier Name, Identifier Name contain special character $

e) Total_Marks - Valid Identifier Name

f) total-Marks - Valid Identifier Name

g) _Percentage - Valid Identifier Name

d) Total Marks - InValid Identifier Name, Identifier Name cannot have spaces in between 2 word

h) True - InValid Identifier Name, Identifier Name cannot be a keyword.

Q2. Write the corresponding Python assignment statements: 

a) Assign 10 to variable length and 20 to variable breadth. 

length=10

breadth=20

b) Assign the average of values of variables length and breadth to a variable sum.

sum = (length + breadth) / 2

c) Assign a list containing strings ‘Paper’, ‘Gel Pen’, and ‘Eraser’ to a variable  stationery. 

stationery = [‘Paper’, ‘Gel Pen’, ‘Eraser’]

print(stationery)

d) Assign the strings ‘Mohandas’, ‘Karamchand’, and ‘Gandhi’ to variables first, middle and last. 

first = ‘Mohandas’

middle = ‘Karamchand’

last = ‘Gandhi’

print(first)

print(middle)

print(last)

e) Assign the concatenated value of string variables first, middle and last to variable fullname. 

Make sure to incorporate blank spaces appropriately between different parts of names.

fullname = first +” “+middle+” “+last

print(fullname)

Q3. Which data type will be used to represent the following data values and why?

a) Number of months in a year - int (year is in number eg. 2024)

b) Resident of Delhi or not - boolean (because Question is asked)

c) Mobile number - number ( Mobile number is always in numbers)

d) Pocket money - float ( Money can be decimal)

e) Volume of a sphere- float (Volume can be decimal)

f) Perimeter of a square - float (Perimeter can be decimal)

g) Name of the student - String (Because Name can contain only alphabets)

h) Address of the student - String (Because Address can store numbers and alphabets)

Q4. Give the output of the following when num1 = 4, num2 = 3, num3 = 2

A) num1 += num2 + num3

print (num1)

B) num1 = num1 ** (num2 + num3)

print (num1)

C) num1 **= num2 + c

D) num1 = '5' + '5'

print(num1)

print(4.00/(2.0+2.0))

E) num1 = 2+9*((3*12)-8)/10

print(num1)

F) num1 = float(10)

print (num1)

G) num1 = int('3.14')

print (num1)

print(10 != 9 and 20 >= 20)

print(5 % 10 + 10 < 50 and 29 <= 29)

Output:

num1 = 4, num2 = 3, num3 = 2

A) num1 += num2 + num3

print (num1) // 9

B) num1 = num1 ** (num2 + num3)

print (num1) // 59049

C) num1 **= num2 + c // ERROR as c does not contain any value

D) num1 = '5' + '5'

print(num1) // 55 as both the values are string and they will be concat, means they are combined not added.

print(4.00/(2.0+2.0)) // 1.0 First the bracket is solved and than the division will take place.

E) num1 = 2+9*((3*12)-8)/10

print(num1) // 27.2 

Expression will be solved like this:

  2+9*((3*12)-8)/10

Step 1: Solve the inner most brackets

2+9*(36-8)/10

Step 2: Solve the bracket

2+9*28/10

Step 3: as * and / has the same precedence so we will start the evaluation from LEFT to RIGHT.

2+252/10

2+25.2

27.2

F) num1 = float(10)

print (num1)// 10.0 as 10 is an integer and it is converted to float.

G) num1 = int('3.14') // Will give an ERROR as 3.14 is in quotes and cannot convert to int

print (num1)

print(10 != 9 and 20 >= 20) // will print TRUE as both the conditions are TRUE

print(5 % 10 + 10 < 50 and 29 <= 29) will print TRUE as both the conditions are TRUE

Q5. Categorise the following as syntax error, logical error or runtime error:

a) 25 / 0 // LOGICAL ERROR as their is not ERROR in the Statement

b) num1 = 25; num2 = 0; num1/num2 // LOGICAL ERROR as their is not ERROR in the Statement

Q6. Write a Python program to calculate the amount payable if money has been lent on simple interest. Principal or money lent = P, Rate = R% per annum and Time = T years. Then Simple Interest (SI) = (P x R x T)/ 100. 

Amount payable = Principal + SI. 

P, R and T are given as input to the program.

#Principal Amount = P

#Rate = R 

#Time = T 

#Simple Interest = SI

#Amount Payable = AP

# Formulas SI = (P x R x T)/ 100, AP = P + SI

P = 0

R = 0

T = 0

P = float(input("Enter Principal Amount : "))

R = float(input("Enter Rate of Interest : "))

T = float(input("Enter Time (in Years) : "))

SI = (P * R * T) / 100

AP = P + SI 

print("")

print("Amount Payable Calculated ....")

print("Principal Amount : ",P)

print("Rate of Interest : ",R)

print("Time in Years : ",T)

print("Simple Interest : ",SI)

print("Amount Payable : ",AP)

Q7. Write a program to repeat the string ‘‘GOOD MORNING” n times. Here n is an integer entered by the user.

n = 0

x = 0

n = int(input(“Enter number of Times you want to print Good Morning : “))

while x <= n:

print(“GOOD MORNING”)

x = x + 1

Q8. Write a program to find the average of 3 numbers.

num1 = 0

num2 = 0

num3 = 0

avg = 0

num1 = float(input(“Enter First Number : “))

num2 = float(input(“Enter Second Number : “))

num3 = float(input(“Enter Third Number : “))

avg = num1 + num2 + num3

print(“First Number : “,num1)

print(“Second Number : “,num2)

print(“Third Number : “,num3)

print(“Average of 3 Numbers : “,avg)

Q9. Write a program that asks the user to enter one's name and age. Print out a message addressed to the user that tells the user the year in which he/she will turn 100 years old.

name = ""

age = 0

noofyear=0

name = input("Enter your Name : ")

age = int(input("Enter your Age : "))

noofyear = 100 - age

print("Your Name is : ",name)

print("Your age is : ",age)

print(noofyear," years till you turn 100 Years Old.")

Q10. What is the difference between else and elif construct of if statement?

Ans:

If you have one condition then you will use if else statement, but if you have multiple conditions to check, we have to use if elif .. else statement.

Examples are: 

Q11. Find the output of the following program segments:

a)

 for i in range(20,30,2):

     print(i)

Output:

20

22

24

26

28

b)

country = 'INDIA'

for  i in country:

     print (i)

Output:

I

N

D

I

A

c) i = 0; sum = 0

while i < 9:

     if i % 4 == 0:

             sum = sum + i

     i = i + 2

print (sum)

Output:

12

Case Study Based QuestIon

Schools use “Student Management Information System” (SMIS) to manage student related data. This system provides facilities for:

Recording and maintaining personal details of students.

 • Maintaining marks scored in assessments and computing results of students.

 • Keeping track of student attendance, and 

• Managing many other student-related data in the school. 

Let us automate the same step by step.

Identify the personal details of students from your school identity card and write a program to accept these details for all students of your school and display them in this format.