Input and Output in Python (CBSE Class 11 Computer Science)

Every Python program interacts with the user by accepting input and displaying output. The input() function is used to receive data from the user, while the print() function displays information on the screen. Understanding these functions is essential for writing interactive Python programs.

Learning Objectives

• Understand Input and Output.
• Learn the input() function.
• Learn the print() function.
• Understand escape sequences.
• Use sep and end parameters.
• Display formatted output.

Input and Output

User
   │
   ▼
input()
   │
Process
   │
   ▼
print()
   │
   ▼
Output on Screen

Input Function

The input() function is used to accept data from the keyboard. Whatever the user enters is returned as a string.

Syntax

variable = input("Message")

Example 1

name = input("Enter your name: ")

print(name)

Sample Output

Enter your name: Aman

Aman

Example 2: Numeric Input

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

print(age)

Since input() returns a string, int() converts it into an integer.

Output Function

The print() function displays messages, variables, and results on the screen.

Syntax

print(value1, value2, ...)

Example

name = "Riya"

marks = 95

print(name)

print(marks)

Output

Riya

95

Printing Multiple Values

name = "Riya"

marks = 95

print(name, marks)

Output

Riya 95

The sep Parameter

The sep parameter specifies the separator between multiple values printed by the print() function.

Syntax

print(value1, value2, sep="separator")

Example

print("Python", "CBSE", "Class 11", sep=" | ")

Output

Python | CBSE | Class 11

The end Parameter

By default, the print() function moves the cursor to the next line after displaying the output. The end parameter changes this behavior.

Syntax

print(value, end="...")

Example

print("Python", end=" ")

print("Programming")

Output

Python Programming

Escape Sequences

Escape sequences are special character combinations beginning with a backslash (\) that perform special functions while displaying output.

Examples of Escape Sequences

New Line (\n)

print("Python\nProgramming")

Output

Python

Programming

Tab (\t)

print("Name\tMarks")

Output

Name    Marks

Printing Quotes

print("He said \"Hello\"")

Output

He said "Hello"

Formatted Output Using f-Strings

Python provides formatted string literals (f-strings) to insert variable values directly into a string. This feature is available in Python 3.6 and later.

Syntax

name = "Aman"

marks = 95

print(f"{name} scored {marks} marks.")

Output

Aman scored 95 marks.

Dry Run Example

Program

name = input("Enter Name: ")

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

print(name, age)

Dry Run Table

Think Like a Programmer

Predict the output.

print("A", "B", "C", sep="-")

print("Python", end=" ")

print("Programming")

A-B-C

Python Programming

Output Prediction Challenge

name = "Riya"

marks = 92

print(name, marks, sep=" : ")

print("Result", end=" => ")

print("Pass")

Riya : 92

Result => Pass

Real-Life Example

Consider an ATM machine:

• The ATM asks for your PIN → Input
• The ATM processes your request.
• The ATM displays your account balance → Output

Similarly, Python programs accept input, process it, and display output.

Common Beginner Mistakes

• Forgetting that input() returns a string.
• Not converting numeric input using int() or float().
• Confusing sep and end.
• Using incorrect escape sequences.
• Missing quotation marks in print() statements.

Visual Memory Box

Memory Trick

Exam Tips

CBSE Important Questions

2 Marks

1. Differentiate between input() and print().
2. What is the purpose of the sep parameter?

3 Marks

1. Explain escape sequences with suitable examples.
2. Write a program to accept a student's name and marks and display them using sep.

5 Marks

1. Explain the input() and print() functions with syntax, examples, escape sequences, and formatted output.

Practice Yourself

1. Write a program to accept your name and city and display them.
2. Write a program to accept two numbers and display their sum.
3. Display a table using the \t escape sequence.
4. Use sep to print values separated by a comma.
5. Use end to print multiple words on the same line.

Frequently Asked Questions (FAQs)

1. What does the input() function return?

It always returns a string.

2. Which function is used to display output?

print().

3. What is the purpose of the sep parameter?

It specifies the separator between multiple values printed by print().

4. What is the default value of the end parameter?

The default value is \n (new line).

5. Which escape sequence inserts a new line?

\n.

Summary

• input() accepts data from the user and returns it as a string.
• print() displays output on the screen.
• The sep parameter changes the separator between printed values.
• The end parameter changes how a print() statement ends.
• Escape sequences such as \n and \t help format output.
• Input and output functions are used in almost every Python program.