PCEP Data Types, Variables, Basic I/O and Operators — Timed 10 Questions

Question 1

A developer runs the script and enters 'Alice' and '25'. What does it print?

Accepted Answer

Alice is 25 years old.. The input() function returns strings. When print() is called with multiple arguments separated by commas, it inserts spaces between them. Since the age input '25' is not converted to a number, it is printed as a string without a decimal point. Thus, the output is 'Alice is 25 years old.'

Answer

Alice is 25.0 years old.

Answer

Alice is  Alice  is 25 years old.

Answer

Alice is 25 years old. (with age as integer)

Question 2

Given the exhibit, what does the code print?

Accepted Answer

3.0. The code likely performs floor division with at least one float operand (e.g., print(7.0 // 2) or print(7 // 2.0)). Floor division // returns the largest integer less than or equal to the quotient, but if either operand is a float, the result is a float. Since 7.0 // 2 = 3.0, the output is 3.0. If both operands were integers, the result would be the integer 3, not 3.0. Thus option A (3.0) is correct.

Answer

3

Answer

3.5

Answer

3.5

Question 3

A company runs a Python script on a server that monitors network traffic. The script reads a configuration file containing a threshold value as a string, e.g., '0.85'. The script compares this threshold to a calculated load average (float). The developer writes: threshold = config['threshold']; if load > threshold: alert(). The alert never triggers even when load exceeds 0.85. The config file is correctly parsed. What is the most likely cause and solution?

Accepted Answer

The threshold is a string; convert it to float before comparison.. The configuration file stores the threshold as a string ('0.85'), but in Python 3, comparing a float to a string raises a TypeError, not a silent failure. The script may have a try-except block that catches this, or it crashes. The developer must explicitly convert the threshold to a float using float(config['threshold']) before the comparison.

Answer

The config file key is misspelled; check spelling.

Answer

Use a try-except block to catch TypeError.

Answer

The load variable is a string; convert to float.

Question 4

Refer to the exhibit. What is the printed value?

Accepted Answer

35. The expression in the exhibit is (2+3)*(5+2). Parentheses have the highest precedence, so we first evaluate the two addition operations: 2+3=5 and 5+2=7. Then we multiply the results: 5*7=35. Therefore, the printed value is 35, corresponding to option D.

Answer

27

Answer

5

Answer

21

Question 5

A developer needs to swap the values of two variables a and b without using a temporary variable. Which single line of code correctly performs the swap?

Accepted Answer

a, b = b, a. Python supports tuple unpacking, which allows swapping the values of two variables in a single line without a temporary variable. The expression `a, b = b, a` evaluates the right-hand side tuple `(b, a)` first, then assigns the values to `a` and `b` respectively, effectively swapping them. Option A fails because after `a = b`, the original value of `a` is lost, so `b = a` assigns the same value to both. Option C (XOR swap) works but requires three statements, not a single line. Option D (arithmetic swap) also works but requires three statements and may cause overflow in other languages, though Python handles big integers; still, it is not a single line.

Answer

a = b; b = a

Answer

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

Answer

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

Question 6

A developer is working on a project that requires handling large numbers. They write:

x = 10000000000
y = 3.0
z = x / y
print(int(z))

The output is 3333333333. However, the developer expected 3333333333 (same). But they suspect that integer division might be better. They try:

x = 10000000000
y = 3
z = x // y
print(z)

Output: 3333333333. Both give same. Now they test with negative numbers:

x = -10
y = 3
z1 = x / y
z2 = x // y
print(z1, z2)

The output is -3.3333333333333335 and -4. The developer is confused why z2 is -4 instead of -3. Which of the following explains the behavior?

Accepted Answer

Floor division always rounds down toward negative infinity, so -10 // 3 = -4 because -3.33 floor is -4.. Python's floor division (`//`) always rounds down toward negative infinity, not toward zero. For `-10 // 3`, the exact result is approximately -3.333, and the floor (largest integer ≤ the value) is -4, not -3. This is consistent with the mathematical definition of floor division used in Python. Option B is incorrect because Python's `//` is not truncation; it is floor division, and Python does not have a bug. Options A and D also misstate the behavior.

Answer

The division operator / rounds toward zero, while // rounds toward negative infinity.

Answer

Truncation division always rounds toward zero, so -10 // 3 should be -3, but Python has a bug.

Answer

The result depends on the types; using float y yields different result.

Question 7

A developer writes the following code: x = 5; y = 2; print(x // y). What is the output?

Accepted Answer

2. The floor division operator (//) in Python returns the largest integer less than or equal to the result of the division. Since 5 divided by 2 equals 2.5, the floor is 2, and the result is an integer (int) because both operands are integers. Therefore, the output is 2.

Answer

1

Answer

2.0

Answer

2.5

Question 8

A junior developer writes: x = 10; y = 3; print(x % y). What will be printed?

Accepted Answer

1. The modulo operator (%) returns the remainder of the division of the left operand by the right operand. Here, 10 divided by 3 equals 3 with a remainder of 1, so print(x % y) outputs 1.

Answer

3.33

Answer

0

Answer

3

Question 9

A developer needs to convert a string '25' to an integer and then add 10. Which code correctly performs this?

Accepted Answer

print(int('25') + 10). `int('25')` converts the string '25' to the integer 25, and then `+ 10` performs integer addition, resulting in 35. The `print()` function outputs the result. This follows Python's type conversion rules where explicit conversion is required to combine a string and an integer in arithmetic.

Answer

print('25' + 10)

Answer

print(int('25') + '10')

Answer

print('25' + str(10))

Question 10

What is the correct way to read a floating-point number from user input and store it in a variable?

Accepted Answer

x = float(input()). `float(input())` first reads the user input as a string via `input()`, then converts that string to a floating-point number using the `float()` function. This is the standard and only valid way in Python to obtain a float from console input, as `input()` always returns a string.

Answer

x = input(float())

Answer

x = input() as float

Answer

x = input().float()