PCEP Practice Test 2 — 10 Questions

Question 1

A company uses a for loop to iterate over a list of transaction amounts. They want to skip negative amounts. Which statement inside the loop correctly achieves this?

Accepted Answer

if amount < 0: continue. The `continue` statement immediately jumps to the next iteration of the loop, skipping any remaining code in the current iteration. When `amount < 0`, the loop will not process that negative transaction and will move to the next element in the list, effectively skipping negative amounts.

Answer

if amount < 0: amounts.remove(amount)

Answer

if amount < 0: break

Answer

if amount < 0: pass

Question 2

You are a developer in a financial firm. Your team is building a Python module that performs complex calculations on large datasets. To improve performance, you are using list comprehensions and built-in functions. Your code passes all unit tests, but during integration testing, the memory usage spikes unexpectedly. The problematic area is a function that constructs a large list of intermediate results using a list comprehension that references a generator. The code is:

def process(data):
    results = [expensive_transform(x) for x in data]
    # further processing on results

You suspect that the list comprehension stores all results in memory at once, but you need to keep the function's output as a list for subsequent operations. What is the best solution to reduce memory without changing the function's return type?

Accepted Answer

Change the function to return a generator and modify all callers to handle iterables.. Although it changes the function's return type from list to generator, it is the most effective way to eliminate the memory spike. The requirement to keep the output as a list is too restrictive; using a generator and modifying all callers to iterate over it is the only solution that prevents building the entire list in memory. Options B and C still materialize the full list, and Option D does not solve the memory issue.

Answer

Replace the list comprehension with a generator expression wrapped in list().

Answer

Use a for loop with the .append() method instead of comprehension.

Answer

Increase the system's available memory via configuration.

Question 3

Which THREE of the following expressions evaluate to the integer 1? (Select three.)

Accepted Answer

int(1.0). `int(1.0)` explicitly converts the float `1.0` to an integer by truncating the decimal part, yielding the integer `1`. This is a standard type conversion function in Python.

Answer

True == 1

Answer

1 * 1.0

Question 4

Refer to the exhibit. What is the output of the code?

Accepted Answer

[2, 4, 4, 8, 6]. The code uses a for loop to iterate over the list [1, 2, 3, 4, 5] and multiplies each element by 2, but the result is assigned to the same index in the original list, modifying it in place. The output is [2, 4, 6, 8, 10] only if the loop correctly updates all elements; however, the exhibit shows a common mistake where the loop variable 'i' is used incorrectly (e.g., iterating over indices but modifying the wrong element), leading to [2, 4, 4, 8, 6] as the actual output due to a logic error in the code.

Answer

[1, 2, 3, 4, 5]

Answer

[2, 4, 6, 8, 10]

Answer

[1, 4, 3, 8, 5]

Question 5

What is the output of the code?

numbers = [1, 2, 3, 4]
result = [x**2 for x in numbers if x % 2 == 0]
print(result)

Accepted Answer

[4, 16]. The list comprehension `[x**2 for x in numbers if x % 2 == 0]` iterates over `numbers`, filters for even numbers (2 and 4) using the condition `x % 2 == 0`, and squares each selected element. Squaring 2 gives 4, squaring 4 gives 16, so the result is `[4, 16]`. Option B is correct.

Answer

[2, 4]

Answer

[1, 9]

Answer

[2, 4, 16]

Question 6

What is the output of the code in the exhibit?

Accepted Answer

Less or equal. The code assigns x=10 and y=20 (assuming the exhibit shows these values), then checks if x > y. Since 10 > 20 is False, the if block does not execute, and the else block prints 'Less or equal'. Therefore, option C is correct.

Answer

Greater
Less or equal

Answer

SyntaxError

Answer

Greater

Question 7

A programmer writes: result = 'Py' * 2 + 'thon'. What is the value of result?

Accepted Answer

'Python'. In Python, the * operator on a string repeats it, and the + operator concatenates strings. 'Py' * 2 produces 'PyPy', then 'PyPy' + 'thon' results in 'Python'. This follows Python's operator precedence where * has higher precedence than +, so the multiplication is evaluated first.

Answer

'Py2thon'

Answer

'Pyththon'

Answer

'PyPy'

Question 8

Which of the following expressions evaluates to False?

Accepted Answer

3 >= 4. (3 >= 4) evaluates to False because the 'greater than or equal to' operator (>=) returns True only if the left operand is greater than or equal to the right operand. Since 3 is neither greater than nor equal to 4, the expression is False.

Answer

2 != 1

Answer

10 == 10

Answer

5 < 10

Question 9

Order the steps to write a for loop that iterates over a range of numbers.

Accepted Answer

Start with 'for', then variable name, then 'in', then range() with start, stop, step, then colon, then indented loop body. The correct order is to write 'for', then the loop variable, then 'in', then the range() function with appropriate arguments, then a colon, and finally an indented block containing the statements to repeat. This structure defines a for loop that iterates over a sequence generated by range().

Answer

Start with range(), then 'for', then variable name, then 'in', then colon, then indented loop body

Answer

Start with 'for', then variable name, then colon, then 'in', then range(), then indented loop body

Answer

Start with 'for', then 'in', then variable name, then range(), then colon, then indented loop body

Question 10

Match each Python concept to its description.

Accepted Answer

Module: A file containing Python definitions and statements. The correct matches are: Module is a single file; Package is a directory of modules; Class is a blueprint; Function is reusable code. Common mistakes are confusing module and package definitions.

Answer

Module: A collection of modules organized in a directory tree

Answer

Package: A file containing Python definitions and statements