For–else execution behavior in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this for–else code?

Consider the following Python code snippet. What will it print when executed?

Python

for i in range(3):
    print(i)
else:
    print('Done')

A

0
1
2
Done

B

0
1
2

C Done

D

0
1
Done

💡 Hint

The else block runs after the for loop completes normally without break.

The else block after a for loop runs only if the loop finishes all iterations without a break.

Here, the loop prints 0, 1, 2 and then the else prints 'Done'.

❓ Predict Output

intermediate

What is the output when break is used inside for loop with else?

What will this code print when run?

Python

for i in range(5):
    if i == 2:
        break
    print(i)
else:
    print('Finished')

A

0
1
Finished

B

0
1
2
Finished

C

0
1

D

0
1
2

💡 Hint

The else block does not run if the loop is exited by break.

The loop breaks when i == 2, so it prints 0 and 1 only.

The else block is skipped because of the break.

🧠 Conceptual

advanced

When does the else block run in a for–else structure?

Choose the correct statement about the execution of the else block in a for–else loop.

A The else block runs only if the for loop has zero iterations.

B The else block runs only if the for loop contains a break statement.

C The else block runs after every iteration of the for loop.

D The else block runs only if the for loop completes all iterations without a break.

💡 Hint

Think about what happens when break is used inside the loop.

The else block runs only if the loop finishes normally without encountering a break.

If break is used, else is skipped.

❓ Predict Output

advanced

What is the output of this nested for–else code?

Analyze the code below and select the output it produces.

Python

for x in range(2):
    for y in range(3):
        if y == 1:
            break
        print(f'{x},{y}')
    else:
        print('Inner else')
else:
    print('Outer else')

A

0,0
Inner else
1,0
Inner else
Outer else

B

0,0
1,0
Outer else

C

0,0
1,0
Inner else
Outer else

D

0,0
1,0

💡 Hint

Remember the else after inner loop runs only if inner loop completes without break.

The inner loop breaks when y == 1, so inner else is skipped both times.

The outer loop completes normally, so outer else runs.

❓ Predict Output

expert

How many items are in the dictionary after this for–else code runs?

What is the number of items in the dictionary d after executing this code?

Python

d = {}
for i in range(5):
    if i == 3:
        break
    d[i] = i * 2
else:
    d['done'] = True
print(len(d))

A 3

B 4

C 5

D 1

💡 Hint

Check if the else block runs when break is used.

The loop breaks when i == 3, so only keys 0,1,2 are added.

The else block is skipped, so 'done' key is not added.

Length is 3.