PCEP Computer Programming and Python Fundamentals Practice Test 2 — 15 Questions

Question 1

A data scientist has a list: scores = [88, 92, 79, 93, 85]. They want to add 5 bonus points to each score and store the new scores. Which code accomplishes this?

Accepted Answer

scores = [s + 5 for s in scores]. Uses a list comprehension to create a new list where each element is the original score plus 5. This correctly generates the new scores without modifying the original list, which is the intended behavior.

Answer

scores = [s+5] for s in scores

Answer

for s in scores: s += 5

Answer

scores = scores + 5

Question 2

A developer wants to extract the file extension from a filename: 'report.pdf'. Which string method will return 'pdf'?

Accepted Answer

'report.pdf'.split('.')[-1]. The `split('.')` method divides the string at each period, returning a list `['report', 'pdf']`. Accessing index `-1` retrieves the last element, which is the file extension `'pdf'`. This is a common Python idiom for extracting file extensions.

Answer

'report.pdf'.replace('.', '')

Answer

'report.pdf'.split('.')[1]

Answer

'report.pdf'.removeprefix('report.')

Question 3

Which THREE of the following will correctly iterate over all keys and values of a dictionary d = {'a':1, 'b':2}?

Accepted Answer

for k in d: print(d[k]). Option B is correct because iterating directly over a dictionary yields its keys, so `for k in d: print(d[k])` accesses each key and then prints its corresponding value via subscripting. Option D is correct because `d.items()` returns a view of (key, value) tuples, allowing `for k, v in d.items():` to unpack and iterate over both keys and values simultaneously. Option E is correct because `d.keys()` explicitly returns the dictionary's keys, and `print(d[k])` then retrieves each associated value, achieving full key-value iteration. Option A is incorrect because `enumerate(d)` yields index-key pairs (e.g., (0, 'a'), (1, 'b')), not key-value pairs, so `i, k` would bind the index and key rather than the key and value. Option C is incorrect because `d.values()` iterates only over the values, not the keys, so it does not satisfy the requirement to iterate over all keys and values.

Answer

for i, k in enumerate(d):

Answer

for v in d.values(): print(v) -- only values

Question 4

Consider the following code:

x = input('Enter a number: ')
print(x + x)

A user enters 5 at the prompt. What is printed?

Accepted Answer

55. 55 because Python's input() function returns a string. When the user enters 5, it is stored as the string '5'. If the code then uses the + operator to concatenate this string with itself (e.g., print(input() + input()) or print(x + x)), the result is '55', not numeric addition.

Answer

10

Answer

5

Answer

25

Question 5

The above JSON is loaded into a Python dictionary named data using json.load(). A developer writes:
print(data['languages'][1][:3])
What is printed?

Accepted Answer

Jav. The JSON data is loaded into a Python dictionary. The key 'languages' maps to a list of strings. Indexing with [1] retrieves the second element, which is 'Java'. Then slicing with [:3] extracts the first three characters, resulting in 'Jav'. Therefore, option B is correct.

Answer

IndexError

Answer

Java

Answer

Pyt

Question 6

A programmer writes the following code:

if x > 5:
print('Greater')

What is the most likely cause of an IndentationError?

Accepted Answer

The print statement is not indented.. In Python, the colon at the end of an if statement signals the start of an indented block. The print statement must be indented (typically 4 spaces) to be part of that block. Without indentation, Python raises an IndentationError because it expects a suite of statements under the if clause.

Answer

The comparison operator is wrong.

Answer

The variable x is undefined.

Answer

The colon after the condition is missing.

Question 7

Which of the following is the most efficient (Pythonic) way to create a list of squares for numbers 0 through 9?

Accepted Answer

squares = [i*i for i in range(10)]. Uses a list comprehension, which is the most Pythonic and efficient way to create a list because it combines iteration and list construction in a single, readable expression. It avoids the overhead of repeated method calls (like `append`) and is faster than `map` with a lambda due to reduced function call overhead.

Answer

squares = []; for i in range(10): squares.append(i*i)

Answer

squares = list(map(lambda x: x*x, range(10)))

Answer

squares = (i*i for i in range(10))

Question 8

Which TWO of the following are valid Python variable names? (Choose two.)

Accepted Answer

_private. Option D, _private, is a valid Python identifier because it begins with an underscore, which is an allowed leading character, and contains only letters and underscores. Option E, my_var, is valid because it uses only letters and the underscore character, with no leading digit or hyphen. Option A, for, is rejected because for is a reserved keyword in Python and cannot be used as an identifier. Option B, my-var, is invalid because hyphens are not permitted in Python variable names (they are interpreted as the subtraction operator). Option C, 1var, is invalid because Python identifiers cannot begin with a digit.

Answer

for

Answer

my-var

Answer

1var

Question 9

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 10

Which of the following is a correct way to comment multiple lines in Python?

Accepted Answer

""" comment """. Triple-quoted strings (''' or """) in Python can be used as multi-line comments when they are not assigned to a variable, as they are ignored by the interpreter as expressions. This is a common practice for documenting code or temporarily disabling multiple lines.

Answer

// comment

Answer

/* comment */

Answer

# comment (each line)

Question 11

Which TWO of the following are valid variable names in Python? (Choose Two)

Accepted Answer

_myVar. Option B, `_myVar`, is a valid Python identifier because it starts with an underscore, which is allowed, and contains only letters and underscores with no illegal characters. Option E, `my_var`, is also valid since it begins with a letter and uses only letters, digits, and underscores, matching Python's identifier rules (letters, digits, and underscores, not starting with a digit). Option A, `my-var`, is invalid because the hyphen is not permitted in identifiers; it would be parsed as subtraction. Option C, `2ndValue`, is invalid because identifiers cannot begin with a digit. Option D, `class`, is invalid because it is a reserved keyword in Python and cannot be used as a variable name.

Answer

my-var

Answer

2ndValue

Answer

class

Question 12

Refer to the exhibit. What is the output?

Accepted Answer

6 and 12. The code begins with a = 3. The first print(a * 2) outputs 6. Then a is reassigned to a + 6, making a = 9. The second print(a + 3) outputs 12. Therefore, the output is 6 and 12, which corresponds to option A.

Answer

6 and 7

Answer

9 and 12

Answer

3 and 3

Question 13

Refer to the exhibit. What is printed?

Accepted Answer

x greater. The code defines x = 10 and y = 5. The if-elif-else structure first checks if x > y, which is true (10 > 5), so it prints 'x greater' and skips the remaining conditions. Therefore, option B is correct.

Answer

None

Answer

equal

Answer

y greater

Question 14

A Python function is designed to return the first element of a list. However, when passed an empty list, it raises an IndexError. Which best practice should be applied to handle this robustly?

Accepted Answer

Check if len(lst) > 0 before accessing lst[0].. Checking the length of the list before accessing an index is the most explicit and readable way to avoid an IndexError. This approach follows the principle of 'look before you leap' (LBYL), which is a common defensive programming pattern in Python. It clearly communicates the intent to handle empty lists without relying on exception handling for normal control flow.

Answer

Use try-except to catch IndexError and return None.

Answer

Always return None; let the caller handle IndexError.

Answer

Use a default parameter like lst=[0] to avoid empty list.

Question 15

Refer to the exhibit. What is the output?

Accepted Answer

16. The expression in the exhibit is `print(2 ** 3 * 2)`. In Python, exponentiation has higher precedence than multiplication, so `2 ** 3` is evaluated first (result 8), then multiplied by 2 to give 16. Therefore, the output is 16.

Answer

2

Answer

4

Answer

8