Taking input using input() in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this code when input is '5'?

Consider the following Python code that takes input and processes it:

Python

num = input("Enter a number: ")
result = int(num) * 2
print(result)

A 10

B 55

C TypeError

D 5

💡 Hint

Remember that input() returns a string and you need to convert it to an integer before multiplying.

The input '5' is read as a string. Using int() converts it to the number 5. Multiplying by 2 gives 10, which is printed.

❓ Predict Output

intermediate

What will be printed if the input is 'hello'?

Look at this code snippet:

Python

user_input = input("Say something: ")
print(user_input * 3)

A TypeError

B hellohellohello

C hello 3 times with spaces

D hello3

💡 Hint

Multiplying a string by a number repeats the string that many times.

The input 'hello' is a string. Multiplying it by 3 repeats it three times without spaces.

❓ Predict Output

advanced

What error does this code raise if input is 'abc'?

Analyze this code:

Python

value = int(input("Enter a number: "))
print(value + 10)

A ValueError

B TypeError

C SyntaxError

D 10abc

💡 Hint

int() cannot convert non-numeric strings to integers.

Trying to convert 'abc' to int causes a ValueError because 'abc' is not a valid number.

❓ Predict Output

advanced

What is the output if the input is '3 4'?

Consider this code:

Python

a, b = input("Enter two numbers separated by space: ").split()
print(int(a) + int(b))

A 34

B ValueError

C 7

D TypeError

💡 Hint

split() divides the input string into parts separated by spaces.

Input '3 4' splits into '3' and '4'. Converting both to int and adding gives 7.

❓ Predict Output

expert

What is the output of this code if input is '10'?

Examine this code carefully:

Python

num = input("Enter a number: ")
match num:
    case '10':
        print("Ten")
    case _:
        print("Not Ten")

A TypeError

B Not Ten

C SyntaxError

D Ten

💡 Hint

match-case compares the input string exactly to the case values.

Input '10' matches the case '10', so it prints 'Ten'.

Practice

1. What does the input() function do in Python?

easy

A. It stops the program immediately.

B. It prints text on the screen.

C. It asks the user to type something and returns it as text.

D. It converts text to numbers automatically.

Solution

1. Step 1: Understand the purpose of input()

   The input() function waits for the user to type something and press Enter.

2. Step 2: Identify what input() returns

   It always returns the typed data as a string (text), not numbers or other types.

3. Final Answer:

   It asks the user to type something and returns it as text. -> Option C

4. Quick Check:

   input() returns text [OK]

Hint: Remember: input() always returns text, never numbers directly [OK]

Common Mistakes:

• Thinking input() prints text
• Assuming input() stops the program
• Believing input() converts text to numbers automatically

2. Which of the following is the correct way to ask the user for their name using input()?

easy

A. name = input Enter your name:

B. name = input('Enter your name: ')

C. name = input['Enter your name:']

D. name = input{Enter your name:}

Solution

1. Step 1: Check the syntax of input() with prompt

   The prompt must be inside parentheses and quotes, like input('prompt').

2. Step 2: Identify the correct option

   Only name = input('Enter your name: ') uses parentheses and quotes correctly to show the prompt.

3. Final Answer:

   name = input('Enter your name: ') -> Option B

4. Quick Check:

   Prompt text inside parentheses and quotes [OK]

Hint: Use parentheses and quotes for prompt text in input() [OK]

Common Mistakes:

• Missing parentheses around prompt
• Using brackets or braces instead of parentheses
• Not putting prompt text inside quotes

3. What will be the output of this code if the user types 25 when asked?

age = input('Enter your age: ')
print(age + 5)

medium

A. 30

B. 255

C. 5

D. TypeError

Solution

1. Step 1: Understand input() returns a string

   The variable age will be the string '25', not the number 25.

2. Step 2: Analyze the print statement

   age + 5 attempts to add a string and an integer. In Python, this causes a TypeError, but if the code was print(age + '5'), it would concatenate to '255'. Since the code is print(age + 5), it raises a TypeError.

3. Final Answer:

   TypeError -> Option D

4. Quick Check:

   String + int causes TypeError [OK]

Hint: input() returns text; convert to int before adding numbers [OK]

Common Mistakes:

• Assuming input() returns number
• Trying to add int to string without conversion
• Expecting automatic type conversion

4. Find the error in this code snippet:

number = input('Enter a number: ')
result = number * 2
print(result)

medium

A. number is a string, multiplying repeats text instead of doubling number

B. input() should be replaced with print()

C. Missing parentheses in print statement

D. No error, code works fine

Solution

1. Step 1: Identify the type of number

   The input() function returns a string, so number is text.

2. Step 2: Understand what number * 2 does for strings

   Multiplying a string by 2 repeats it twice, so if user types '3', result is '33', not 6.

3. Final Answer:

   number is a string, multiplying repeats text instead of doubling number -> Option A

4. Quick Check:

   String * 2 repeats text, not math multiply [OK]

Hint: Convert input to int before math operations [OK]

Common Mistakes:

• Assuming input returns number
• Expecting string * 2 to double value
• Ignoring type conversion

5. You want to ask the user for two numbers and print their sum. Which code correctly does this?

hard

A. a = int(input('First number: '))
b = int(input('Second number: '))
print(a + b)

B. a = input('First number: ')
b = input('Second number: ')
print(a + b)

C. a = input('First number: ')
b = input('Second number: ')
print(int(a) + b)

D. a = input('First number: ')
b = int(input('Second number: '))
print(a + b)

Solution

1. Step 1: Convert inputs to numbers

   To add numbers, convert both inputs from strings to integers using int().

2. Step 2: Add the converted numbers

   Only a = int(input('First number: ')) b = int(input('Second number: ')) print(a + b) converts both inputs before adding, so it sums correctly.

3. Final Answer:

   a = int(input('First number: ')) b = int(input('Second number: ')) print(a + b) -> Option A

4. Quick Check:

   Convert both inputs to int before adding [OK]

Hint: Convert all inputs to int before math [OK]

Common Mistakes:

• Adding strings instead of numbers
• Converting only one input
• Forgetting to convert inputs