250+ TOP MCQs on Python While and For Loops and Answers

Python Multiple Choice Questions on “While and For Loops”.

1. What will be the output of the following Python code?

x = ['ab', 'cd']
for i in x:
    i.upper()
print(x)

a) [‘ab’, ‘cd’]
b) [‘AB’, ‘CD’]
c) [None, None]
d) none of the mentioned
Answer: a
Clarification: The function upper() does not modify a string in place, it returns a new string which isn’t being stored anywhere.

2. What will be the output of the following Python code?

x = ['ab', 'cd']
for i in x:
    x.append(i.upper())
print(x)

a) [‘AB’, ‘CD’]
b) [‘ab’, ‘cd’, ‘AB’, ‘CD’]
c) [‘ab’, ‘cd’]
d) none of the mentioned
Answer: d
Clarification: The loop does not terminate as new elements are being added to the list in each iteration.

3. What will be the output of the following Python code?

i = 1
while True:
    if i%3 == 0:
        break
    print(i)
 
    i + = 1

a) 1 2
b) 1 2 3
c) error
d) none of the mentioned
Answer: c
Clarification: SyntaxError, there shouldn’t be a space between + and = in +=.

4. What will be the output of the following Python code?

i = 1
while True:
    if i%0O7 == 0:
        break
    print(i)
    i += 1

a) 1 2 3 4 5 6
b) 1 2 3 4 5 6 7
c) error
d) none of the mentioned
Answer: a
Clarification: Control exits the loop when i becomes 7.

5. What will be the output of the following Python code?

i = 5
while True:
    if i%0O11 == 0:
        break
    print(i)
    i += 1

a) 5 6 7 8 9 10
b) 5 6 7 8
c) 5 6
d) error
Answer: b
Clarification: 0O11 is an octal number.

6. What will be the output of the following Python code?

i = 5
while True:
    if i%0O9 == 0:
        break
    print(i)
    i += 1

a) 5 6 7 8
b) 5 6 7 8 9
c) 5 6 7 8 9 10 11 12 13 14 15 ….
d) error