PCAP Practice Test 5 — 10 Questions

Question 1

Consider the following code snippet:

try:
    x = int(input())
    y = 10 / x
    print(y)
except ZeroDivisionError:
    print('Division by zero')
except ValueError:
    print('Invalid integer')

If the user enters '0', what is the output?

Accepted Answer

Division by zero. When the user enters '0', the input is successfully converted to the integer 0 by int(), so no ValueError occurs. Then 10 / 0 raises a ZeroDivisionError, which is caught by the except ZeroDivisionError block, printing 'Division by zero'. Option C is correct because the code never reaches the ValueError handler.

Answer

No output

Answer

Both 'Invalid integer' and 'Division by zero'

Answer

Invalid integer

Question 2

Which expression returns the last character of string s?

Accepted Answer

s[-1]. Python uses zero-based indexing for strings, where negative indices count from the end. s[-1] directly accesses the last character of the string, as -1 refers to the final element in the sequence.

Answer

s[len(s)]

Answer

s[-0]

Answer

s[0]

Question 3

Refer to the exhibit. If the file config.cfg exists but the user does not have read permission, what will be printed?

Accepted Answer

'Permission denied'. When `open()` is called on a file that exists but the user lacks read permission, Python raises a `PermissionError`. Since no exception handling is present, the exception is unhandled and Python prints a traceback to stderr which includes the error message `'Permission denied'` (among other details). Option B correctly identifies the permission-denied message that appears in the output.

Answer

An unhandled exception is raised

Answer

Nothing; the program continues silently

Answer

'File not found'

Question 4

Which TWO statements about Python strings are correct? (Choose exactly 2 correct answers.)

Accepted Answer

Strings are immutable; operations like concatenation produce a new string.. Python strings are immutable, meaning once a string object is created, its content cannot be changed. Any operation that appears to modify a string, such as concatenation with the + operator, actually creates a brand-new string object in memory, leaving the original unchanged.

Answer

Strings are mutable; you can change individual characters via indexing.

Answer

Strings have an .append() method to add characters at the end.

Answer

You can assign a new character to a position in a string using indexing: s[0] = 'a'.

Question 5

A programmer writes a function to check if a string is a palindrome (ignoring case and non-alphanumeric characters). Which implementation correctly achieves this?

Accepted Answer

def is_pal(s): s = ''.join(c for c in s if c.isalnum()).lower(); return s == s[::-1]. It first filters the string to keep only alphanumeric characters using `c.isalnum()`, converts the result to lowercase with `.lower()`, and then compares the string to its reverse using slicing `s[::-1]`. This correctly handles case insensitivity and ignores non-alphanumeric characters, which is the standard approach for palindrome checking in Python.

Answer

def is_pal(s): s = s.lower(); return s == ''.join(reversed(s))

Answer

def is_pal(s): return s == s[::-1]

Answer

def is_pal(s): s = s.lower(); return s == s[::-1]

Question 6

What is the result of the expression 'Hello' * 3?

Accepted Answer

'HelloHelloHello'. In Python, the multiplication operator (*) on a string repeats the string a specified number of times. 'Hello' * 3 concatenates 'Hello' three times, producing 'HelloHelloHello'. This is a fundamental string operation defined in Python's sequence protocol.

Answer

'Hello3'

Answer

'Hello Hello Hello'

Answer

TypeError

Question 7

Which of the following statements about class inheritance in Python are true? (Choose two.)

Accepted Answer

Abstract base classes can be defined using the ABC module.. Python's `abc` module (Abstract Base Classes) allows you to define abstract base classes by inheriting from `ABC` and using the `@abstractmethod` decorator. This enforces that subclasses must implement the abstract methods, providing a formal interface contract.

Answer

A class can inherit from only one base class.

Answer

A child class can override any method from its parent class, but only if the method is declared as virtual.

Answer

The super() function is used to call a method from a sibling class.

Question 8

Which TWO statements are true regarding strings in Python?

Accepted Answer

Strings can be concatenated with the + operator.. Strings in Python support concatenation using the + operator, which joins two or more strings into a single string. This is a fundamental operation for combining textual data, and it works by creating a new string object that contains the characters from both operands in sequence.

Answer

Strings are not sequences.

Answer

Strings are mutable.

Answer

Strings do not support indexing.

Question 9

Which TWO of the following are correct ways to raise a custom exception in Python? (Assume CustomError and CustomException are user-defined.)

Accepted Answer

raise CustomError("invalid"). It raises a user-defined exception by instantiating the custom exception class `CustomError` with an argument (the string "invalid"). In Python, the `raise` statement must be followed by an exception instance or an exception class; `CustomError("invalid")` creates an instance of the custom exception, which is the proper way to raise a custom exception with a custom message.

Answer

raise "Custom error"

Answer

raise 42

Answer

raise Exception

Question 10

Which TWO of the following are valid uses for the '__name__' variable in a Python module?

Accepted Answer

To check if the module is being run as the main program.. The '__name__' variable is set to the string '__main__' when the module is executed directly as the main program (e.g., via 'python module.py'). This allows a module to include code that runs only when it is the entry point, not when it is imported by another module. The check is typically done with 'if __name__ == "__main__":'.

Answer

To get the file path of the module.

Answer

To control which names are exported when using 'from module import *'.

Answer

To determine which module imported it.