Python Questions and Answers – While and For Loops – 6

This set of Python Technical Questions & Answers focuses on “While/For Loops”.

1. What is the output of the following?

for i in range(10):
    if i == 5:
        break
    else:
        print(i)
else:
    print("Here")

a) 0 1 2 3 4 Here
b) 0 1 2 3 4 5 Here
c) 0 1 2 3 4
d) 1 2 3 4 5
View Answer

Answer: c
Explanation: The else part is executed if control doesn’t break out of the loop.

2. What is the output of the following?

for i in range(5):
    if i == 5:
        break
    else:
        print(i)
else:
    print("Here")

a) 0 1 2 3 4 Here
b) 0 1 2 3 4 5 Here
c) 0 1 2 3 4
d) 1 2 3 4 5
View Answer

Answer: a
Explanation: The else part is executed if control doesn’t break out of the loop.

3. What is the output of the following?

x = (i for i in range(3))
for i in x:
    print(i)

a) 0 1 2
b) error
c) 0 1 2 0 1 2
d) none of the mentioned
View Answer

Answer: a
Explanation: The first statement creates a generator object.

4. What is the output of the following?

x = (i for i in range(3))
for i in x:
    print(i)
for i in x:
    print(i)

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a) 0 1 2
b) error
c) 0 1 2 0 1 2
d) none of the mentioned
View Answer

Answer: a
Explanation: We can loop over a generator object only once.

5. What is the output of the following?

string = "my name is x"
for i in string:
    print (i, end=", ")

a) m, y, , n, a, m, e, , i, s, , x,
b) m, y, , n, a, m, e, , i, s, , x
c) my, name, is, x,
d) error
View Answer

Answer: a
Explanation: Variable i takes the value of one character at a time.

6. What is the output of the following?

string = "my name is x"
for i in string.split():
    print (i, end=", ")

a) m, y, , n, a, m, e, , i, s, , x,
b) m, y, , n, a, m, e, , i, s, , x
c) my, name, is, x,
d) error
View Answer

Answer: c
Explanation: Variable i takes the value of one word at a time.

7. What is the output of the following?

a = [0, 1, 2, 3]
for a[-1] in a:
    print(a[-1])

a) 0 1 2 3
b) 0 1 2 2
c) 3 3 3 3
d) error
View Answer

Answer: b
Explanation: The value of a[-1] changes in each iteration.

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8. What is the output of the following?

a = [0, 1, 2, 3]
for a[0] in a:
    print(a[0])

a) 0 1 2 3
b) 0 1 2 2
c) 3 3 3 3
d) error
View Answer

Answer: a
Explanation: The value of a[0] changes in each iteration. Since the first value that it takes is itself, there is no visible error in the current example.

9. What is the output of the following?

a = [0, 1, 2, 3]
i = -2
for i not in a:
    print(i)
    i += 1

a) -2 -1
b) 0
c) error
d) none of the mentioned
View Answer

Answer: c
Explanation: SyntaxError, not in isn’t allowed in for loops.

10. What is the output of the following?

string = "my name is x"
for i in ' '.join(string.split()):
    print (i, end=", ")

a) m, y, , n, a, m, e, , i, s, , x,
b) m, y, , n, a, m, e, , i, s, , x
c) my, name, is, x,
d) error
View Answer

Answer: a
Explanation: Variable i takes the value of one character at a time.