Control Flow and Functions Flashcards

What does the `global` keyword do inside a function?

Answer: Allows the function to read and modify a global variable

The `global` keyword declares that a name inside a function refers to the module-level variable rather than creating a local one.

What is the output of the following? x = 5 def change(): x = 10 change() print(x)

Answer: 5

Without the `global` keyword, `x = 10` inside `change()` creates a local variable, leaving the global `x` unchanged at 5.

Which loop is guaranteed to execute its body at least once?

Answer: None — Python has no do-while, so neither guarantees one execution

Python does not have a do-while loop, so neither `for` nor `while` guarantees at least one execution; the condition is checked before the first iteration.

What is the output of the following? def counter(n): while n > 0: print(n) n -= 1 counter(3)

Answer: 3 2 1

The loop prints n starting at 3 and decrements until n reaches 0 (not printed), yielding 3, 2, 1.

What is a function's local scope?

Answer: Variables defined inside the function, not visible outside it

Local scope refers to variables defined within a function that are only accessible inside that function during its execution.

What does `range(5, 0, -1)` produce?

Answer: [5, 4, 3, 2, 1]

`range(5, 0, -1)` starts at 5, counts down by 1, and stops before reaching 0, yielding 5, 4, 3, 2, 1.

What is the output of the following code? for i in range(2): for j in range(2): print(i, j)

Answer: 0 0, 0 1, 1 0, 1 1

The nested loops iterate all combinations: (0,0), (0,1), (1,0), (1,1), each printed on a separate line.