PCEP Practice Test 5 — 10 Questions

Question 1

Based on the exhibit, which expression returns 2.5 in Python?

Accepted Answer

5 / 2. The division operator `/` in Python always returns a float, even when dividing two integers. Since 5 divided by 2 equals 2.5, the expression `5 / 2` returns the float `2.5`.

Answer

int(5 / 2)

Answer

5 % 2

Answer

5 // 2

Question 2

A programmer is writing a script to read a number, determine if it is even or odd, and then also use the number to calculate its square. The code:

num = input("Enter a number: ")
if num % 2 == 0:
    print("Even")
else:
    print("Odd")
square = num ** 2
print("Square:", square)

When run, a TypeError occurs on the modulo line. Which fix will resolve the error and allow the later calculation to work?

Accepted Answer

Change the input to: num = int(input("Enter a number: ")). The `input()` function always returns a string, and the modulo operator `%` and exponentiation operator `**` require numeric operands. By converting the input to an integer with `int(input(...))`, both the modulo and exponentiation operations work correctly, resolving the TypeError and allowing the square calculation to proceed.

Answer

Change the condition to: if num // 2 == 0:

Answer

Change the condition to: if float(num) % 2 == 0:

Answer

Change the condition to: if int(num) % 2 == 0:

Question 3

A system administrator wrote a Python script to monitor disk usage. The script reads the output of a system command that returns a string like 'Used: 45%' and extracts the percentage. The code uses slicing to get the numeric part and converts to int. However, on some servers, the output format changes to 'Used: 45.2%', causing a ValueError when converting to int. The administrator needs a robust solution that works with both integer and floating-point percentages while still producing an integer result (e.g., 45 for 45.2%). Which option is the best approach?

Accepted Answer

Use a try-except block to attempt int conversion first; if a ValueError occurs, convert to float and then convert to int (which truncates the decimal part).. It uses a try-except block to first attempt int conversion for integer percentages, and if a ValueError occurs (due to a decimal point), it converts to float and then to int, which truncates the decimal part. This approach handles both '45%' and '45.2%' formats without raising an error, producing an integer result as required.

Answer

Use string splitting to extract the numeric part, then convert to float and round to the nearest integer.

Answer

Use a regular expression to extract the number and convert to float, then convert to int.

Answer

Use the .replace() method to remove the '%' character and then convert to int.

Question 4

What is the output of the following code?
```python
x = 10
y = 3
print(x // y * y + x % y)
```

Accepted Answer

10. The expression `x // y * y + x % y` is evaluated using integer arithmetic. First, `x // y` is floor division: 10 // 3 = 3. Then `3 * y` = 3 * 3 = 9. Then `x % y` = 10 % 3 = 1. Finally, 9 + 1 = 10, which is an integer. Option C is correct because the result is 10 (type int).

Answer

9

Answer

10.0

Answer

9.0

Question 5

A developer writes a script to calculate the average of three numbers: avg = (a + b + c) / 3. If a=5, b=10, c=15, what is the data type of avg?

Accepted Answer

float. In Python, the division operator (/) always returns a float, even when dividing integers that result in a whole number. Here, (5 + 10 + 15) / 3 equals 30 / 3, which yields 10.0, a float. Therefore, the data type of avg is float.

Answer

bool

Answer

int

Answer

str

Question 6

What is the output when the user enters 25?

Accepted Answer

2525. When the user enters 25, the input() function returns the string "25". The print() function then concatenates the string "25" with itself using the + operator, resulting in "2525". This is because the + operator performs string concatenation when both operands are strings, not numeric addition.

Answer

Error

Answer

25

Answer

50

Question 7

Refer to the exhibit. A beginner Python programmer executes the code and gets an error. What is the most likely cause?

Accepted Answer

The variables x and y are of incompatible types for the + operator. The error occurs when the + operator is used between incompatible types, such as a string (x) and an integer (y). In Python, the + operator performs concatenation for strings and addition for numbers, but mixing types without explicit conversion raises a TypeError. The code likely defines x as a string (e.g., '10') and y as an integer (e.g., 5), causing the error.

Answer

The + operator cannot be used with print()

Answer

The variable y should be converted to an integer using int()

Answer

The print function is misspelled

Question 8

Consider: x = True; y = False; z = x and not y or x. What is the value of z?

Accepted Answer

True. The expression `x and not y or x` is evaluated with operator precedence: `not` has the highest precedence, then `and`, then `or`. Given `x = True` and `y = False`, `not y` evaluates to `True`. Then `x and True` is `True and True`, which is `True`. Finally, `True or x` (where `x` is `True`) short-circuits to `True`. Thus, `z` is `True`.

Answer

None

Answer

Error

Answer

False

Question 9

Consider the following code:

def foo(x, y):
    return x * y

result = foo(y=2, 3)

What is the error?

Accepted Answer

A positional argument follows a keyword argument.. In Python, when calling a function, all positional arguments must appear before any keyword arguments. The call `foo(y=2, 3)` violates this rule by placing a positional argument (`3`) after a keyword argument (`y=2`), which raises a SyntaxError. This is enforced by Python's parser to avoid ambiguity in argument binding.

Answer

The function requires at least one argument but none provided.

Answer

Keyword arguments cannot be used in function calls.

Answer

The function definition has too many parameters.

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