PCEP Data Types, Variables, Basic I/O and Operators Practice Test 5 — 15 Questions

Question 1

A beginner writes: x = '10'; y = 20; print(x + y). What happens?

Accepted Answer

Raises TypeError. Python's type system does not allow implicit concatenation of a string and an integer. The variable `x` is a string (`'10'`), and `y` is an integer (`20`). The `+` operator with these types triggers a `TypeError: unsupported operand type(s) for +: 'int' and 'str'` (or vice versa), as Python refuses to guess the programmer's intent.

Answer

Prints 30

Answer

Prints 10 + 20

Answer

Prints 1020

Question 2

Which operator is used to check if two values are equal in Python?

Accepted Answer

==. The == operator is Python's equality comparison operator, used to check if two values are equal. It returns True if the values are equal and False otherwise, making it the standard way to test equality in conditions and expressions.

Answer

=

Answer

eq

Answer

!=

Question 3

A developer writes: a = 3; b = 4; c = a + b / 2. What is the value of c?

Accepted Answer

5.0. In Python, the division operator `/` always returns a float, and operator precedence dictates that division is performed before addition. Thus, `b / 2` evaluates to `4 / 2 = 2.0`, then `a + 2.0` yields `3 + 2.0 = 5.0`. Option D is correct because the result is a float value of 5.0.

Answer

3

Answer

3.5

Answer

5

Question 4

Which TWO of the following are valid ways to create a variable with the integer value 100?

Accepted Answer

x = int('100'). Option C, x = int('100'), is correct because the int() constructor parses the string '100' and returns a genuine integer object with the value 100. Option D, x = 100, is correct because an unquoted numeric literal without a decimal point is directly an integer in Python, so x is bound to the int value 100. Option A, x = 0100, is not a valid way to get the integer 100 in Python 3, where a leading zero on a decimal literal is a syntax error (and in Python 2 it would denote octal 64, not 100). Option B, x = 100.0, creates a float, not an integer, even though its numeric value equals 100. Option E, x = '100', creates a string containing the characters 1, 0, 0, not an integer.

Answer

x = 0100

Answer

x = 100.0

Answer

x = '100'

Question 5

Which THREE of the following expressions evaluate to True?

Accepted Answer

3 == 3. Option A (3 == 3) is correct because the equality operator compares the two integer literals 3 and 3, which are identical, so the expression evaluates to True. Option C ('a' < 'b') is correct because Python compares strings lexicographically by Unicode code point, and the code point of 'a' (97) is less than that of 'b' (98), yielding True. Option E (2 != 1) is correct because the inequality operator returns True when the operands differ, and 2 is not equal to 1. Option B (1 < 0) is not correct because 1 is greater than 0, so the less-than comparison evaluates to False. Option D (4 > 5) is not correct because 4 is less than 5, so the greater-than comparison evaluates to False.

Answer

1 < 0

Answer

4 > 5

Question 6

Which TWO of the following are valid Python data types?

Accepted Answer

str. Option B (str) is correct because str is a built-in Python data type used to represent immutable sequences of Unicode characters, such as 'hello'. Option D (int) is correct because int is a built-in Python data type for arbitrary-precision integers, e.g., 42. Option A (real) is not a Python built-in type; Python uses float for floating-point numbers. Option C (array) is not a built-in Python data type, though the array module provides an array class. Option E (char) is not a Python data type; Python represents single characters as strings of length 1.

Answer

real

Answer

array

Answer

char

Question 7

Which FOUR of the following are correct uses of the print() function?

Accepted Answer

print('Hello', 'World', sep='-'). Option B is correct because print() accepts the keyword argument sep to define the separator between multiple arguments, so print('Hello', 'World', sep='-') outputs Hello-World. Option C is correct because print() can take multiple positional arguments and by default separates them with a single space, producing Hello World. Option D is correct because print('Hello') is the standard way to call print() with a single string argument, outputting Hello followed by a newline. Option E is correct because print() accepts arguments of different types, so print('Hello', 5) outputs Hello 5, converting the integer to its string representation. Option A is not correct because print 'Hello' is Python 2 statement syntax, not a valid call to the print() function in Python 3.

Answer

print 'Hello'

Question 8

What is the data type of z after executing z = 10 / 2?

Accepted Answer

float. Float because in Python, the / operator always performs true division and returns a float, regardless of the operands. This is a fundamental concept tested in the PCEP exam to distinguish between / and //.

Answer

bool

Answer

int

Answer

str

Question 9

You are a data analyst at a retail company. You have a list of sales figures stored as strings in a list: sales = ['100', '200', '300']. You need to calculate the total sum. A colleague suggests using: total = sum(sales). However, this raises a TypeError because sum() requires numeric values. Which approach should you take to correctly calculate the total as an integer?

Accepted Answer

Use total = sum(int(s) for s in sales). Option B uses a generator expression to convert each string element to an integer before passing them to sum(). Option A attempts to catch the TypeError but doesn't convert the strings to numbers. Option C uses str() to convert the numbers to strings, so sum() still receives strings and raises a TypeError. Option D attempts to concatenate strings with +=, resulting in a string, not a numeric total.

Answer

Use total = sum(sales) and catch TypeError

Answer

Use total = sum(map(str, sales))

Answer

Use total = 0; for s in sales: total += s

Question 10

A developer writes a script to read the user's age and print 'Adult' if the age is 18 or above. The code outputs 'Adult' for age 9. What is the most likely cause?

Accepted Answer

The input was not converted to integer.. The most likely cause is that the input was not converted to integer. In Python, the `input()` function returns a string. When comparing strings lexicographically, '9' >= '18' evaluates to True because '9' is greater than '1' in the first character. Thus, the condition `age >= '18'` (or similar) would mistakenly output 'Adult' for age 9. Converting the input to an integer with `int()` ensures numeric comparison, where 9 >= 18 is False.

Answer

The if statement lacked parentheses around the condition.

Answer

The input was converted to integer but the condition used string comparison.

Answer

The condition used >= instead of >.

Question 11

A developer needs to store the result of dividing two numbers, a/b, but only if b is not zero. They write: result = a / b if b != 0 else 'undefined'. What is the data type of result when b is zero?

Accepted Answer

str. When `b` is zero, the expression `a / b if b != 0 else 'undefined'` evaluates to the string literal `'undefined'`. Therefore, the variable `result` is assigned a value of type `str` (string). The conditional expression explicitly returns a string in the else branch, making option D correct.

Answer

float

Answer

NoneType

Answer

bool

Question 12

A script calculates total cost: price = 49.95, quantity = 3, tax_rate = 0.08. The developer writes: total = price * quantity * (1 + tax_rate). The result is printed as 161.838. Which best practice is being violated?

Accepted Answer

Not rounding the result to two decimal places for currency.. When dealing with currency values, best practice dictates rounding to two decimal places to represent cents. The raw result 161.838 is not a valid monetary amount; it should be rounded to 161.84 using `round(total, 2)` or formatted with `:.2f`. This ensures accuracy and avoids confusion in financial calculations.

Answer

Using parentheses unnecessarily.

Answer

Not using an f-string to format the output.

Answer

Using multiplication instead of addition for tax.

Question 13

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

Accepted Answer

_count. Option B, _count, is a valid Python identifier because it begins with an underscore, which is allowed, and contains only letters and underscores. Option E, myVar, is valid because it starts with a letter and uses only alphanumeric characters with no spaces or punctuation. Option A, class, is invalid because it is a reserved keyword in Python and cannot be used as a variable name. Option C, my-var, is invalid because hyphens are not permitted in identifiers; only letters, digits, and underscores are allowed. Option D, 2ndPlace, is invalid because an identifier cannot begin with a digit.

Answer

class

Answer

my-var

Answer

2ndPlace

Question 14

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 15

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.