PCEP Data Types, Variables, Basic I/O and Operators Practice Test 3 — 15 Questions

Question 1

What is the output of the code in the exhibit?

Accepted Answer

3. The code performs integer division using the // operator, which in Python returns the floor of the division result for positive numbers. Since 10 // 3 equals 3 (the integer part of 10/3), the output is 3. Option A is correct because integer division discards the fractional part.

Answer

4

Answer

3.0

Answer

3.3333333333333335

Question 2

You are maintaining a legacy Python 2.7 script that calculates shipping costs. The script reads weight from user input, then calculates cost as weight * 1.5. Recently, the company upgraded to Python 3.9, and now the script raises a TypeError: can't multiply sequence by non-int of type 'float'. The input line is: weight = input('Enter weight: '). You need to fix the script minimally. Which action should you take?

Accepted Answer

Change the input line to weight = float(input('Enter weight: ')). In Python 3.9, `input()` returns a string, not a number. Multiplying a string by a float raises a TypeError. Option D converts the input to a float immediately, which is the minimal fix because it handles both integer and decimal weights correctly without changing the multiplication logic.

Answer

Use Python 2 style input by importing from __future__

Answer

Change the multiplication to cost = float(weight) * 1.5

Answer

Change the input line to weight = int(input('Enter weight: '))

Question 3

A developer writes a script to read user input using input() and then prints it. However, the program crashes when the user enters a number. What is the most likely cause?

Accepted Answer

The input is read as a string, but the code treats it as a number without conversion.. The `input()` function in Python 3 always returns a string, regardless of what the user types. If the user enters a number, the program may crash if the code later performs an operation (like arithmetic or comparison) on that string without first converting it to an integer or float using `int()` or `float()`. This mismatch between the string type and the expected numeric type causes a `TypeError`.

Answer

The script uses Python 2, where input() evaluates input as code.

Answer

The print() function expects a string, but the input is a number.

Answer

The input() function cannot handle numeric input.

Question 4

A program calculates the total price including tax: total = price * 1.08. The variable price is assigned as price = 100.0. After execution, total is 108.0. The developer then changes price to 100. What will total be?

Accepted Answer

108.0. In Python, multiplying an integer (100) by a float (1.08) results in a float (108.0). The expression `price * 1.08` performs implicit type coercion to float, so even when `price` is changed from 100.0 to 100, the result remains 108.0, not 108.

Answer

The program will raise a TypeError

Answer

It depends on the Python version

Answer

108

Question 5

A developer needs to store a large collection of unique user IDs (integers) and quickly check if a new ID already exists. Which data type is most appropriate for this task?

Accepted Answer

set. A set is the most appropriate data type because it stores unordered collections of unique elements and provides O(1) average-time complexity for membership testing using the `in` operator. This makes it ideal for quickly checking if a new user ID already exists without needing to manage keys or maintain order.

Answer

dict

Answer

list

Answer

tuple

Question 6

A programmer writes: x = 5; y = x; x = 3; print(y). What is the output?

Accepted Answer

5. In Python, integers are immutable, and the assignment `y = x` copies the reference to the integer object 5, not the variable itself. When `x` is later reassigned to 3, `y` still points to the original integer object 5, so `print(y)` outputs 5.

Answer

3

Answer

8

Answer

None

Question 7

A developer wants to read a floating-point number from user input and compute its square. Which code snippet correctly accomplishes this?

Accepted Answer

num = float(input()); result = num ** 2. It uses `float(input())` to convert the user's input (which is always a string) into a floating-point number, and then computes the square using the exponentiation operator `**`. This ensures that decimal values are handled correctly, which is required for computing the square of a floating-point number.

Answer

num = input(); result = num * num

Answer

result = input() ** 2

Answer

num = int(input()); result = num ** 2

Question 8

A script uses the // operator with negative numbers. For example, -7 // 2 returns -4. The developer expected -3. Which statement best explains this behavior?

Accepted Answer

The // operator performs floor division, which rounds down to the next lower integer.. In Python, the // operator performs floor division, which always rounds down to the next lower integer (toward negative infinity). For -7 // 2, the exact result is -3.5, and floor division rounds down to -4, not -3. This behavior is defined by the Python language specification and differs from truncation toward zero.

Answer

The // operator uses banker's rounding.

Answer

The // operator truncates toward zero for negative numbers.

Answer

The // operator performs integer division with rounding to the nearest even integer.

Question 9

A developer writes a program to calculate the average of three numbers: a=10; b=20; c=30; avg = a + b + c / 3; print(avg). What is the output?

Accepted Answer

40.0. The expression `a + b + c / 3` follows Python's operator precedence: division (`/`) has higher precedence than addition (`+`), so `c / 3` is evaluated first (30 / 3 = 10.0), then the additions are performed left to right: 10 + 20 + 10.0 = 40.0. The result is a float because division always returns a float in Python 3.

Answer

20.0

Answer

10.0

Answer

60.0

Question 10

A programmer needs to swap the values of two variables a and b without using a temporary variable. Which approach works in Python?

Accepted Answer

a, b = b, a. Python supports tuple unpacking, which allows the values of a and b to be swapped in a single atomic operation: a, b = b, a. This works by creating a tuple (b, a) on the right-hand side, then unpacking it into the variables on the left, effectively swapping the values without a temporary variable.

Answer

a = b; b = a

Answer

a = a ^ b; b = a ^ b; a = a ^ b

Answer

a = b + a; b = a - b; a = a - b

Question 11

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

Accepted Answer

data1. 'data1' starts with a letter and contains only letters and digits, which is allowed by Python's identifier rules. Python variable names must begin with a letter (a-z, A-Z) or underscore, and can be followed by letters, digits, or underscores.

Answer

total$

Answer

my var

Answer

2nd_place

Question 12

Which TWO of the following expressions evaluate to True in Python? (Choose two.)

Accepted Answer

1 == True. In Python, the boolean value `True` is equal to the integer `1` due to the fact that `bool` is a subclass of `int`, and `True` is internally represented as `1`. The comparison `1 == True` evaluates to `True` because Python performs implicit type coercion, converting `True` to `1` before the equality check.

Answer

'0' == 0

Answer

2 == True

Answer

None == False

Question 13

Which THREE of the following are built-in Python data types? (Choose three.)

Accepted Answer

str. `str` is a built-in Python data type used to represent sequences of Unicode characters. It is one of the fundamental immutable sequence types in Python, defined in the language specification and available without importing any module.

Answer

boolean

Answer

array

Question 14

A data analyst uses Python to process a CSV file containing sales data. The file has columns: 'Product', 'Price', 'Quantity'. The analyst writes a script to compute total sales: sum of Price * Quantity for each row. The code reads each row as a list of strings. The analyst uses: total = 0; for row in reader: total += row['Price'] * row['Quantity']; print(total). The script raises a TypeError. What is the best fix?

Accepted Answer

Use float(row[1]) * float(row[2]) instead of row['Price'] * row['Quantity'].. The TypeError occurs because row is a list of strings, so integer indices must be used instead of string keys. Multiplying strings also requires conversion. Option D correctly uses float(row[1]) * float(row[2]) with indices, fixing both issues. Option A only converts to float but still uses invalid string keys.

Answer

Convert Price and Quantity to float before multiplication.

Answer

Change the loop to for i in range(len(reader)): total += reader[i][1] * reader[i][2].

Answer

Use integer multiplication and then convert to float.

Question 15

Order the steps to define and call a function in Python.

Accepted Answer

1. Define function using def keyword, 2. Optionally specify parameters in parentheses, 3. Write the indented function body, 4. Call the function by its name.. Function definition starts with def, then the body, parameters are optional, and calling the function executes it.

Answer

1. Write the indented function body, 2. Define function using def keyword, 3. Optionally specify parameters in parentheses, 4. Call the function by its name.

Answer

1. Define function using def keyword, 2. Write the indented function body, 3. Optionally specify parameters in parentheses, 4. Call the function by its name.

Answer

1. Call the function by its name, 2. Define function using def keyword, 3. Optionally specify parameters in parentheses, 4. Write the indented function body.