Question 1

break exits the loop

Accepted Answer

`break` exits the loop immediately when the condition is met, without printing the value that triggered it. The loop runs for n=0, 1, 2 - printing each - then when n=3 the `break` fires before any `print` call, so 3 is never printed.

Question 2

Ternary expression result

Accepted Answer

The ternary expression evaluates the condition first. Since 55 is less than 60, the condition is false and the expression returns the value after `else`, which is "fail". The `>=` operator is inclusive, so a score of exactly 60 would produce "pass".

Question 3

range() upper bound behavior

Accepted Answer

`range(start, stop)` includes `start` but excludes `stop` - the upper bound is always non-inclusive. So `range(3, 8)` gives 3, 4, 5, 6, 7. This is consistent with Python slicing, where `lst[3:8]` also excludes index 8.

Question 4

Short-circuit evaluation with and

Accepted Answer

Python's `and` operator short-circuits: if the left operand is falsy it returns the left operand immediately, without evaluating the right side. An empty list is falsy, so `lst and lst[0]` returns `lst` itself - the empty list `[]`. Without short-circuiting, `lst[0]` would raise an `IndexError`.

Question 5

zip stops at shorter sequence

Accepted Answer

`zip` stops as soon as the shortest iterable is exhausted. Here `b` has only 2 elements, so the loop runs only twice, pairing (1, 'x') and (2, 'y'). The remaining elements of `a` - 3 and 4 - are silently ignored. Use `itertools.zip_longest` if you need to keep going and fill missing values with a default.

Question 6

continue skips current iteration

Accepted Answer

`continue` skips the rest of the current loop body and jumps straight to the next iteration. When `n` is even the `continue` fires, bypassing the `print`. Odd values - 1, 3, 5 - fall through to the print statement and are printed. Notice 5 is included because `range(1, 6)` stops before 6.

Question 7

enumerate with start parameter

Accepted Answer

`enumerate` accepts an optional `start` keyword argument that sets the first index value. Passing `start=1` makes the counter begin at 1 instead of the default 0, which is handy when you want 1-based numbering for display purposes. The tuple unpacking `i, val` puts the index first and the item second.

Question 8

for/else with and without break

Accepted Answer

The `else` clause on a `for` loop runs only when the loop completes without hitting a `break`. In the first call, `n == 2` triggers `break`, so the `else` is skipped and "found" is returned. In the second call the loop exhausts all elements without breaking, so the `else` runs and "not found" is returned. This pattern avoids a boolean found-flag variable and is a clean Python idiom for search loops.

Question 9

break only exits the innermost loop

Accepted Answer

`break` only exits the loop it is directly inside - not any outer loop. The inner `break` stops the inner `for j` loop when j=1 and i=1, leaving `j` at 1. The outer loop then checks `found` and also breaks, leaving `i` at 1. Python does not have a labeled break like some languages, so the flag-and-check pattern shown here is the standard way to break out of nested loops.

Question 10

range with negative step

Accepted Answer

`range(10, 0, -3)` starts at 10 and counts down by 3, stopping before it reaches 0 (the stop value is exclusive). The sequence is 10, 7, 4, 1. Adding those gives 10 + 7 + 4 + 1 = 22. A common mistake is including 0 in the sum or forgetting that the stop is exclusive when counting downward, which would incorrectly give 22 + (-2) or 22 + 0.

Control Flow