PCEP Computer Programming and Python Fundamentals Practice Test 8 — 15 Questions

Question 1

A developer wrote: a, b, c = 10, 20, 30; avg = a + b + c / 3; print(avg). What is the output?

Accepted Answer

40.0. Operator precedence in Python dictates that division (/) has higher precedence than addition (+). Therefore, the expression `a + b + c / 3` is evaluated as `a + b + (c / 3)`, which is `10 + 20 + (30 / 3) = 10 + 20 + 10.0 = 40.0`. The result is a float because division always returns a float in Python 3.

Answer

60.0

Answer

20.0

Answer

30.0

Question 2

A programmer needs to read a file line by line and process each line. Which of the following is the most memory-efficient and Pythonic approach?

Accepted Answer

with open('file.txt') as f: for line in f: print(line). It uses a `with` statement to ensure the file is properly closed after the block, and iterating directly over the file object reads one line at a time without loading the entire file into memory. This is both memory-efficient and Pythonic, as it leverages the file object's built-in iterator.

Answer

lines = open('file.txt').read().split('
')

Answer

content = open('file.txt').read().splitlines()

Answer

for line in open('file.txt'): print(line)

Question 3

A Python script calculates the area of a circle: radius = 5; area = 3.14 * radius ** 2; print(area). What is printed?

Accepted Answer

78.5. 78.5 because the expression `3.14 * radius ** 2` is evaluated according to Python's operator precedence: exponentiation (`**`) has higher precedence than multiplication (`*`), so `radius ** 2` computes 5 squared (25), then multiplied by 3.14 gives 78.5. The `print(area)` function outputs this value.

Answer

157.0

Answer

25.0

Answer

31.4

Question 4

A program uses a for loop to double each element in a list: numbers = [1, 2, 3, 4, 5]; for num in numbers: num = num * 2. After execution, numbers remains unchanged. Why?

Accepted Answer

Reassigning num does not modify the original list element; you need to modify via index.. In Python, the loop variable `num` is a reference to each element in the list, but reassigning `num` (e.g., `num = num * 2`) merely rebinds the local variable to a new integer object; it does not modify the original list element. To change the list in place, you must access elements by their index, such as `numbers[i] = numbers[i] * 2`.

Answer

The assignment creates a new list, leaving the original unchanged.

Answer

Lists are immutable; their elements cannot be changed.

Answer

The variable num is a copy of the list element.

Question 5

A programmer wants to create a function that can accept any number of keyword arguments and store them in a dictionary. Which function definition is correct?

Accepted Answer

def func(**kwargs):. The **kwargs parameter in a function definition collects any number of extra keyword arguments into a dictionary. The double asterisk (**) is the Python syntax for capturing keyword arguments, and 'kwargs' is the conventional name for the resulting dictionary.

Answer

def func(kwargs):

Answer

def func(**args):

Answer

def func(*kwargs):

Question 6

A Python program prompts the user for their age and stores it in a variable. Which is the correct way to convert the input to an integer?

Accepted Answer

age = int(input("Age: ")). The `input()` function in Python always returns a string, and to perform arithmetic operations or numeric comparisons, the string must be explicitly converted to an integer using the `int()` constructor. This is a fundamental requirement for type conversion in Python when handling user input.

Answer

age = str(input("Age: "))

Answer

age = float(input("Age: "))

Answer

age = input("Age: ")

Question 7

A developer needs to check if a number is positive and even. Which conditional expression is correct?

Accepted Answer

if num > 0 and num % 2 == 0:. Python uses the keyword `and` for logical conjunction, and the equality operator is `==` (not `=`). The expression `num > 0 and num % 2 == 0` correctly checks that `num` is both greater than zero and divisible by 2 with no remainder, which defines a positive even number.

Answer

if num > 0 & num % 2 == 0:

Answer

if num > 0 and num % 2 = 0:

Answer

if num > 0 && num % 2 == 0:

Question 8

A function is supposed to modify a list passed as argument by appending an element. However, after calling the function, the original list remains unchanged. Which is the most likely cause?

Accepted Answer

The function reassigns the list parameter instead of mutating it.. In Python, when a list is passed to a function, the parameter refers to the same list object. If the function reassigns the parameter (e.g., `lst = [1, 2, 3]`), it only changes the local reference, not the original list. To modify the original list, the function must mutate it in-place using methods like `append()` or `extend()`, not reassign the parameter.

Answer

The list is immutable.

Answer

The list is a tuple.

Answer

The function uses a local variable that shadows the global list.

Question 9

Refer to the exhibit. Which of the following is true about the output?

Accepted Answer

Prints "Error: invalid literal for int() with base 10: 'abc'" then "Done". The code attempts to convert the string 'abc' to an integer using int('abc'), which raises a ValueError. The except block catches this exception and prints 'Error:' followed by the exception message, then the finally block always executes and prints 'Done'. Thus, the output is 'Error: invalid literal for int() with base 10: 'abc'' followed by 'Done'.

Answer

Prints "Error:" then "Done" without the message

Answer

Raises an unhandled exception

Answer

Prints only "Done"

Question 10

Which two of the following are correct ways to create a dictionary in Python? (Choose two.)

Accepted Answer

my_dict = dict(a=1, b=2). Option B, my_dict = dict(a=1, b=2), is correct because the dict() constructor accepts keyword arguments, using the parameter names as string keys and the assigned values as their values, producing {'a': 1, 'b': 2}. Option D, my_dict = {'a':1, 'b':2}, is correct because it uses standard dictionary literal syntax with curly braces, colon-separated key-value pairs, and comma separators. Option A is invalid because bare identifiers a and b are treated as variables rather than string keys, so it raises a NameError unless those variables exist, and even then it would not create the intended string-keyed dictionary. Option C is invalid because dict() expects a single iterable of key-value pairs (e.g., dict([('a',1),('b',2)])), not multiple separate list arguments. Option E is invalid because square brackets denote a list, and the colon syntax inside them is not valid Python.

Answer

my_dict = {a:1, b:2}

Answer

my_dict = dict(['a',1],['b',2])

Answer

my_dict = ["a":1, "b":2]

Question 11

Which two of the following are true about Python lists? (Choose two.)

Accepted Answer

Lists can contain elements of different data types.. Option A is correct because Python lists are heterogeneous ordered collections, so a single list may hold elements of different data types (e.g., [1, 'two', 3.0, True]) without any type restriction. Option E is correct because the built-in len() function returns the number of elements in a list, such as len([10, 20, 30]) returning 3. Option B is incorrect because lists are mutable and therefore unhashable, so they cannot be used as dictionary keys (a TypeError is raised). Option C is incorrect because Python uses zero-based indexing, so the first element is at index 0, not 1. Option D is incorrect because lists are mutable: elements can be added, removed, or reassigned in place via methods like append(), remove(), or item assignment.

Answer

Lists can be used as dictionary keys.

Answer

Lists are indexed starting from 1.

Answer

Lists are immutable.

Question 12

A junior developer writes a Python script to calculate the average of three numbers: avg = a + b + c / 3. What is the problem with this code?

Accepted Answer

Missing parentheses cause incorrect order of operations. Python follows the standard mathematical order of operations (PEMDAS/BODMAS), where division has higher precedence than addition. The expression `a + b + c / 3` is evaluated as `a + b + (c / 3)`, which calculates the average incorrectly. To compute the correct average, parentheses must be used: `(a + b + c) / 3`.

Answer

Division by a variable is not allowed

Answer

Python cannot divide integers

Answer

Variable names are too short

Question 13

A developer writes a function that modifies a global variable inside the function:

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

When called, an error occurs. What is the correct way to fix this?

Accepted Answer

Use 'global count' inside the function. The error occurs because Python treats 'count' as a local variable inside the function due to the assignment, but it is referenced before assignment. Using 'global count' inside the function explicitly tells Python to use the global variable, allowing modification. This is the correct fix for modifying a global variable from within a function.

Answer

Define count inside the function

Answer

Use the 'static' keyword

Answer

Pass count as an argument to the function

Question 14

A developer wants to create a list of even numbers from 0 to 10 inclusive. Which code snippet will correctly produce [0, 2, 4, 6, 8, 10]?

Accepted Answer

All of the above. All three code snippets produce the list [0, 2, 4, 6, 8, 10]. Option A uses the built-in `range()` function with a step of 2, starting at 0 and stopping before 11. Option B is a list comprehension that iterates over range(11) and filters numbers where the remainder when divided by 2 is 0. Option C multiplies each integer from 0 to 5 by 2, yielding the same even numbers. Therefore, D is correct.

Answer

list(range(0,11,2))

Answer

[x for x in range(11) if x%2==0]

Answer

[x*2 for x in range(6)]

Question 15

A beginner writes: x = 10; y = 3; print(x // y). What is the output?

Accepted Answer

3. The // operator in Python performs floor division, which returns the largest integer less than or equal to the result of the division. Since 10 divided by 3 equals 3.333..., the floor of that value is 3, and because both operands are integers, the result is an integer (3), not a float.

Answer

1

Answer

3.0

Answer

3.333