Python Control Flow: Loops 4

Question 1

What does `zip([1,2,3], ['a','b'])` produce when iterated?

Accepted Answer

(1,'a'), (2,'b')

Answer

`zip()` stops at the shortest iterable, so only (1,'a') and (2,'b') are produced.

Question 2

What is a list comprehension equivalent to `for x in range(5): result.append(x**2)`?

Accepted Answer

`[x**2 for x in range(5)]`

Answer

A list comprehension with square brackets `[expr for var in iterable]` produces a list.

Question 3

Which of the following correctly uses `while` with an `else` clause?

Accepted Answer

`while x > 0:
    x -= 1
else:
    print('done')`

Answer

The `else` clause is at the same indentation level as `while`, not inside the loop body.

Question 4

How many times does this loop print?
```
for _ in range(3):
    for _ in range(2):
        print('x')
```

Accepted Answer

6

Answer

The inner loop prints 2 times per outer iteration, and the outer runs 3 times: 3×2 = 6.

Question 5

What does `range(5, 5)` produce?

Accepted Answer

An empty range

Answer

When start equals stop, `range()` produces no values — it's an empty sequence.

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