PCEP Computer Programming and Python Fundamentals Practice Test 6 — 15 Questions

Question 1

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

Accepted Answer

_myVar. In Python, variable names can start with an underscore, and `_myVar` follows the naming rules: it begins with a letter or underscore, contains only letters, digits, or underscores, and is not a reserved keyword. Underscore-prefixed names are commonly used for internal or private variables by convention.

Answer

my-var

Answer

2ndValue

Answer

class

Question 2

Which TWO of the following statements about Python's for loop are correct? (Choose Two)

Accepted Answer

It can iterate over any sequence. A `for` loop in Python is designed to iterate over any iterable sequence, such as lists, tuples, strings, dictionaries, or ranges. This is a fundamental property of the `for` loop, which retrieves each item from the sequence in order until the sequence is exhausted.

Answer

It can be used with a while loop condition

Answer

It always executes at least once

Answer

It is the only loop in Python

Question 3

Which THREE of the following are valid ways to create a list with elements 1, 2, 3? (Choose Three)

Accepted Answer

[1,2,3]. It uses the literal list syntax with square brackets and commas to directly create a list containing the integers 1, 2, and 3. This is the most straightforward and explicit way to define a list in Python.

Answer

(1,2,3)

Answer

{1,2,3}

Question 4

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 5

Refer to the exhibit. What is the most likely cause of this error?

Accepted Answer

Variable x is used before assignment. The error message indicates that variable 'x' is being referenced before it has been assigned a value. In Python, using a variable that has not been defined yet raises a NameError. Option B correctly identifies this as the cause.

Answer

Variable x is a string

Answer

Variable x is an integer

Answer

Variable x is misspelled

Question 6

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 7

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 8

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 9

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 10

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 11

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 12

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 13

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 14

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 15

Refer to the exhibit. What is the output?

Accepted Answer

[1, 4, 3, 16, 5]. The code iterates over the list [1, 2, 3, 4, 5] and for each element, if it is even, it squares it; otherwise, it leaves it unchanged. The resulting list is [1, 4, 3, 16, 5], which matches option B.

Answer

[1, 2, 3, 4, 5]

Answer

[1, 2, 9, 4, 25]

Answer

[1, 4, 9, 16, 25]