PCEP Variable Scope and the `global` keyword 2

Question 1

What will the following code print?

x = 10
def foo():
    x = 20
foo()
print(x)

Accepted Answer

10

Answer

The assignment inside foo() creates a local variable; the global x remains 10.

Question 2

Which statement correctly describes the LEGB rule in Python?

Accepted Answer

Local, Enclosing, Global, Built-in — the order Python searches for names

Answer

LEGB stands for Local, Enclosing, Global, Built-in — Python's name resolution order.

Question 3

What error occurs when you read a variable inside a function before assigning it, if the same name exists globally?

Accepted Answer

UnboundLocalError

Answer

Python detects the assignment later in the function and marks the name as local, so reading it before assignment raises UnboundLocalError.

Question 4

What does the following code output?

count = 0
def increment():
    global count
    count += 1
increment()
increment()
print(count)

Accepted Answer

2

Answer

global count lets increment() modify the module-level variable, so two calls produce 2.

Question 5

Which of the following is a valid use of the global keyword?

Accepted Answer

global x; x = 5

Answer

The global statement declares the name, then a separate assignment sets the value; combining them on one line with = is a SyntaxError.

(PCEP) Certified Entry-Level Python Programmer Practice Test