PCEP Data Types, Variables, Basic I/O and Operators Practice Test 9 — 15 Questions

Question 1

A developer writes: num = input('Enter a number: '); result = num * 2; print(result). If the user enters 5, what is the output?

Accepted Answer

55. The `input()` function always returns a string. When the user enters '5', `num` is the string '5', not the integer 5. The `*` operator on a string performs repetition, so `'5' * 2` produces '55', which is printed as 55.

Answer

Error: cannot multiply string by int

Answer

10

Answer

'5' * 2

Question 2

A developer needs to check if a variable x is between 10 and 20 (inclusive). Which expression is correct?

Accepted Answer

10 <= x <= 20. Python supports chained comparison operators, allowing `10 <= x <= 20` to evaluate whether `x` is between 10 and 20 inclusive. This expression is equivalent to `(10 <= x) and (x <= 20)`, which checks both boundaries simultaneously.

Answer

x > 10 and x < 20

Answer

x < 10 and x < 20

Answer

x >= 10 or x <= 20

Question 3

What is the output of: print(10 // 3, 10 % 3)?

Accepted Answer

3 1. The // operator performs floor division, returning the integer quotient (10 // 3 = 3), and the % operator returns the remainder (10 % 3 = 1). The print function outputs these two values separated by a space.

Answer

3.3333 1

Answer

3.0 1.0

Answer

1 3

Question 4

A developer accidentally wrote: print('Hello' + 5). What happens?

Accepted Answer

It raises a TypeError. In Python, the `+` operator is overloaded for string concatenation only when both operands are strings. Attempting to concatenate a string (`'Hello'`) with an integer (`5`) violates Python's strong dynamic typing rules, which do not perform implicit type coercion for this operation. This raises a `TypeError` with a message like 'can only concatenate str (not "int") to str'.

Answer

It prints 'Hello' and ignores the 5

Answer

It prints a warning but still runs

Answer

It prints 'Hello5'

Question 5

Which TWO of the following Python data types are mutable?

Accepted Answer

list. Option A (list) is correct because Python lists are mutable sequence types: you can change, add, or remove elements in place (e.g., append(), item assignment) without creating a new object. Option E (dict) is correct because dictionaries are mutable mappings: key-value pairs can be added, updated, or deleted in place (e.g., d['k'] = v, del d['k']). The unmarked options are immutable: str (B) cannot be modified in place since strings are immutable sequences, tuple (C) is an immutable sequence whose contents cannot be reassigned, and int (D) is an immutable numeric type where any arithmetic produces a new object rather than modifying the original.

Answer

str

Answer

tuple

Answer

int

Question 6

Which THREE of the following are valid Python variable names?

Accepted Answer

myVar2. Option A, myVar2, is a valid Python identifier because it starts with a letter and contains only letters and digits, with no reserved characters. Option C, _myVar, is valid because a leading underscore is permitted in Python identifiers and is commonly used to signal internal or private names. Option D, value, is valid because it is a plain sequence of letters that does not collide with any Python keyword. Option B, my-var, is invalid because the hyphen is not allowed in identifiers and would be parsed as subtraction. Option E, 2ndValue, is invalid because Python identifiers cannot begin with a digit.

Answer

my-var

Answer

2ndValue

Question 7

Which THREE of the following are Python data types?

Accepted Answer

str. Option A, str, is correct because str is Python's built-in immutable text/string type, used for sequences of Unicode characters. Option C, bool, is correct because bool is a built-in subclass of int representing the two truth values True and False. Option D, float, is correct because float is Python's built-in floating-point type, typically implemented as a C double for real numbers. Option B, math, is not a data type but a standard-library module that provides mathematical functions. Option E, None, is not a data type but the singleton object None, whose type is NoneType.

Answer

math

Answer

None

Question 8

What is the output when the following code is executed?

try:
    print(1/0)
except ZeroDivisionError:
    print("Cannot divide by zero")

Accepted Answer

Cannot divide by zero. The code inside the try block attempts to divide by zero, which raises a ZeroDivisionError. The except block catches this exception and executes its print statement, outputting 'Cannot divide by zero'.

Answer

The program crashes with an unhandled exception

Answer

Result: 0

Answer

Unsupported operand

Question 9

What is the output of the following code?

config = {}
print('Not set' if config.get('timeout') is None else config.get('timeout'))

Accepted Answer

Not set. The code attempts to access a dictionary key 'timeout' that does not exist. Using square bracket access on a missing key raises a KeyError, but the code uses the .get() method, which returns None by default if the key is missing. Since the key 'timeout' is not in the dictionary, .get('timeout') returns None, and the print statement outputs 'Not set' because the condition `config.get('timeout') is None` evaluates to True.

Answer

KeyError: 'timeout'

Answer

None

Answer

False

Question 10

What is the output from the interactive Python session?

Accepted Answer

3 1. The expression `10 // 3` performs integer (floor) division, which discards the fractional part and returns the integer quotient 3. The expression `10 % 3` returns the remainder of the division, which is 1. Therefore, the output is `3 1`, making option B correct.

Answer

3.333 1

Answer

1 3

Answer

3 0

Question 11

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 12

A program prompts a user for their age using input(). Which line of code correctly stores the age as an integer?

Accepted Answer

age = int(input("Enter age: ")). The `int()` function explicitly converts the string returned by `input()` into an integer, which is required for storing a numeric age value. The `input()` function always returns a string in Python, so without conversion, arithmetic operations would fail or produce unexpected results.

Answer

age = str(input("Enter age: "))

Answer

age = float(input("Enter age: "))

Answer

age = input("Enter age: ")

Question 13

Which of the following expressions evaluates to False?

Accepted Answer

3 >= 4. (3 >= 4) evaluates to False because the 'greater than or equal to' operator (>=) returns True only if the left operand is greater than or equal to the right operand. Since 3 is neither greater than nor equal to 4, the expression is False.

Answer

2 != 1

Answer

10 == 10

Answer

5 < 10

Question 14

A developer writes: total = 2 ** 3 + 4. What is the value of total?

Accepted Answer

12. In Python, the exponentiation operator (**) has higher precedence than addition (+). Therefore, 2 ** 3 is evaluated first, yielding 8. Then 8 + 4 equals 12. Option B is correct.

Answer

16

Answer

14

Answer

10

Question 15

A developer wrote: x = 10; y = 5; x += y * 2. What are the values of x and y after execution?

Accepted Answer

x=20, y=5. The expression `x += y * 2` is evaluated as `x = x + (y * 2)`. Given `x = 10` and `y = 5`, `y * 2` equals 10, then `x + 10` equals 20, so `x` becomes 20. The value of `y` remains unchanged at 5 because the assignment operator `+=` only modifies `x`.

Answer

x=15, y=5

Answer

x=30, y=5

Answer

x=20, y=10