For–else execution behavior in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the else block do in a for–else statement?

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

beginner

When is the else block skipped in a for–else loop?

The else block is skipped if the for loop is exited early using a break statement.

beginner

True or False: The else block in a for–else loop runs after every iteration.

False. The else block runs only once after the loop finishes all iterations without a break.

beginner

What is a real-life analogy for a for–else loop?

Imagine checking every item in a box for a defect. If you find a defect, you stop (break). If you check all items and find none defective, you celebrate (else).

beginner

Write a simple Python for–else example that prints 'Found it!' if a number 5 is in a list, otherwise prints 'Not found!'.

numbers = [1, 2, 3, 4, 6] for num in numbers: if num == 5: print('Found it!') break else: print('Not found!')

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

A Only if the loop contains a break

B After every iteration of the loop

C After the loop finishes all iterations without a break

D Before the loop starts

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

What happens if a break is executed inside a for loop with an else?

A An error occurs

B The <code>else</code> block is skipped

C The loop restarts

D The <code>else</code> block runs immediately

If break is executed, the loop exits early and the else block does not run.

Which of these is a correct use of for–else?

A Running code after every loop iteration

B Skipping loop iterations

C Replacing <code>if</code> statements

D Searching for an item and doing something if not found

for–else is useful to run code if the loop did not find what it was searching for.

What will this code print?

for i in range(3):
    if i == 1:
        break
else:
    print('Done')

A Nothing

B Done

C 0 1 2

D Error

The loop breaks when i == 1, so the else block does not run and nothing is printed.

Can for–else be used without a break statement?

A Yes, but else always runs then

B No, break is required

C Yes, else never runs

D No, syntax error

If no break is used, the else block runs after the loop finishes.

Explain how the else block works in a for–else loop and when it runs.

Think about what happens if the loop never breaks.

Describe a real-life situation where a for–else loop would be useful.

Imagine checking items one by one for a problem.