PCEP Computer Programming and Python Fundamentals Practice Test 7 — 15 Questions

Question 1

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 2

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

Accepted Answer

value_2. Python variable names can contain letters, digits, and underscores, and must start with a letter or underscore. 'value_2' starts with a letter and uses an underscore, making it valid.

Answer

value-2

Answer

2nd_value

Answer

for

Question 3

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). The `dict()` constructor accepts keyword arguments, where each keyword becomes a string key and its argument becomes the corresponding value. This creates `{'a': 1, 'b': 2}`. Option D is correct because it uses the standard literal syntax with colon-separated key-value pairs inside curly braces, which is the most common way to define a dictionary.

Answer

my_dict = {a:1, b:2}

Answer

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

Answer

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

Question 4

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

Accepted Answer

Lists can contain elements of different data types.. Only two options are correct: A and E. Option A is correct because Python lists can contain elements of different data types. Option E is correct because len() returns the number of elements in a list. Options B, C, D are incorrect: B is wrong because lists are mutable and unhashable, hence cannot be dictionary keys; C is wrong because index starts at 0; D is wrong because lists are mutable.

Answer

Lists can be used as dictionary keys.

Answer

Lists are indexed starting from 1.

Answer

Lists are immutable.

Question 5

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 6

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. To modify a global variable inside a function, the global keyword must be used to declare the variable as global.

Answer

Define count inside the function

Answer

Use the 'static' keyword

Answer

Pass count as an argument to the function

Question 7

A company is developing a data processing pipeline that must handle large datasets efficiently. They notice that using a list comprehension to filter data is slower than expected. Which alternative approach would likely improve performance?

Accepted Answer

Using a generator expression. Generator expressions produce items lazily, one at a time, without storing the entire filtered result in memory. This reduces memory overhead and can improve performance when processing large datasets, as the pipeline can iterate over generated items without building a full list first.

Answer

Using the map() function

Answer

Using a for loop with append

Answer

Using a lambda function

Question 8

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 9

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

Question 10

A developer is writing a script to process user input. The script should repeatedly ask for a number until a valid integer is entered. Which loop structure is most appropriate?

Accepted Answer

while loop with a condition. A while loop with a condition is the most appropriate because it allows the script to repeatedly prompt for input until a valid integer is entered, checking the condition before each iteration. In Python, the while loop continues as long as the condition evaluates to True, making it ideal for indefinite iteration where the number of repetitions is unknown beforehand. This pattern is commonly used with a try-except block to validate integer conversion.

Answer

for loop

Answer

do-while loop

Answer

Recursion

Question 11

A developer writes: print('Hello' + 5). What is the result?

Accepted Answer

TypeError. In Python, the + operator performs string concatenation only when both operands are strings. Attempting to concatenate a string ('Hello') with an integer (5) raises a TypeError because Python does not implicitly convert the integer to a string for concatenation. This is a fundamental type safety feature of the language.

Answer

Hello 5

Answer

SyntaxError

Answer

Hello5

Question 12

A company has a Python script that imports a module from a package. The package structure is: mypackage/__init__.py, mypackage/module.py. The script uses 'from mypackage import module'. Which file must exist for this import to work?

Accepted Answer

mypackage/__init__.py. For a Python import like 'from mypackage import module' to work, the directory 'mypackage' must be recognized as a package. This requires the presence of an __init__.py file inside it (even if empty), which signals to Python that the directory is a package and allows its submodules to be imported. Option B is correct because __init__.py is the file that makes 'mypackage' a package.

Answer

mypackage.py

Answer

module.py in the current directory

Answer

Only mypackage/module.py is needed

Question 13

A script uses 'import math' then calls 'math.sqrt(-1)'. What is the outcome?

Accepted Answer

ValueError. `math.sqrt()` in Python's math module does not support negative arguments; it raises a `ValueError` when given a negative number, as the function is designed for real numbers only. The error message is 'math domain error', indicating the input is outside the domain of the mathematical function.

Answer

NaN

Answer

A complex number

Answer

AttributeError

Question 14

Refer to the exhibit. What is the output when the following code is executed: print(calculate_discount(100, 0.6))

Accepted Answer

Discount too high followed by 100. The code defines a function `calculate_discount(price, discount)` that first checks if the discount is 0.6 or higher. Since 0.6 is exactly equal to 0.6, the condition `if discount >= 0.6` is true, so it prints 'Discount too high' and then returns the original price (100). The `print()` statement outside the function outputs the return value, which is 100, resulting in the output 'Discount too high' followed by '100' on the next line.

Answer

Discount too high

Answer

40.0

Answer

100

Question 15

Refer to the exhibit. What is the output?

Accepted Answer

Invalid integer. The code attempts to convert the string '12.5' to an integer using int(). Since '12.5' is not a valid integer literal (it contains a decimal point), Python raises a ValueError. The exception is caught by the except clause, which prints 'Invalid integer'. After the try-except block, there is no further print statement, so the only output is 'Invalid integer'.

Answer

Invalid integer
Some error

Answer

No output

Answer

Some error