Python Programming - Unit 2

Q1. What are errors? Explain the following types of errors:

• Syntax
• logical
• runtime error

Errors are problems in a program that causes the program to stop its execution. On the other hand, exceptions are raised when some internal events change the program's normal flow.

• Syntax Errors
  • occur when the code doesn't follow Python's rules, like using incorrect grammar in English.
  • Python stops and points out the issue before running the program.
• Logical Errors
  • Subtle bugs in the program that allow the code to run, but produce incorrect or unintended results.
  • These are often harder to detect since the program doesn’t crash, but the output is not as expected.
• Runtime Errors
  • A runtime error in a program is an error that occurs while the program is running after being successfully compiled.
  • Runtime errors are commonly called referred to as "bugs" and are often found during the debugging process GeeksForGeeks(Syntax and Logical Errors)

GeeksForGeeks(Runtime Errors)

Q2. What is an exception? Explain Exception Handling and Describe about any four types of built-in exceptions.

An exception in Python is an error that occurs during program execution, interrupting the normal flow of the program.

• Exception handling allows you to manage these errors gracefully using try and except blocks, so your program can respond to problems without crashing

try:
    # Code that might raise an exception
except ExceptionType:
    # Code to handle the exception

Common Built-in exceptions

ZeroDivisionError: Raised when you try to divide by zero.

try:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero")

ValueError: Raised when a function receives an argument of the correct type but an inappropriate value (e.g., converting a letter to int).

try:
    num = int("abc")
except ValueError:
    print("Invalid value for integer conversion")

TypeError: Raised when an operation is applied to an object of inappropriate type (e.g., adding a string and an integer).

try:
    result = "2" + 3
except TypeError:
    print("Cannot add string and integer")

NameError: Raised when a variable is not defined.

try:
    print(x)
except NameError:
    print("Variable x is not defined")

Python Docs

Q3. Differentiate between syntax error and exception.

Feature	Syntax Error	Exception
Definition	Error caused by violating Python's grammar or syntax rules	Error detected during program execution (runtime error)
When Occurs	During code parsing, before execution starts	During program execution, after code is syntactically correct
Example	if True print("Hello") (missing colon)	10 / 0 (division by zero)
Handling	Cannot be handled with try-except; must fix the code	Can be handled using try-except blocks
Effect	Prevents the program from running at all	Interrupts normal flow, but program can recover if handled
Error Message Type	SyntaxError, IndentationError, etc.	ZeroDivisionError, ValueError, NameError, etc.

Q4. Describe strings in python with any four operations performed on strings.

A string is a sequence of characters.

• Python treats anything inside quotes as a string.
• This includes letters, numbers, and symbols.
• Python has no character data type so single character is a string of length 1.
• It is an iterable sequence.
• Single Line strings are made by wrapping single or double quotes around a sentence
  • Eg. "Hello" or 'Hello'
• Multiline Strings are made by wrapping content in three single/double quotes
  • Eg. ``` """Hello World"""

Method	Description	Example	Expected Output
capitalize()	Converts the first character to upper case	"hello world".capitalize()	Hello world
casefold()	Converts string into lower case	"HELLO WORLD".casefold()	hello world
center()	Returns a centered string	"hello".center(11, '*')	***hello***
count()	Returns the number of times a specified value occurs in a string	"banana".count("a")	3

W3Schools

Q5. What is a raw string?

In Python, a raw string is a string literal prefixed with an r or R.

• The primary purpose of raw strings is to treat backslashes (\) as literal characters
• preventing them from being interpreted as escape sequences.

eg.

print("Hello \there") # Expected Output: Hello 	here
print(r"Hello \there") # Expected Output: Hello \there

Q6. Program to display multiplication table

for i in range(1,11):
    print(f"5 x {i} = {5*i}")

Show Output

5 x 1 = 5
5 x 2 = 10
5 x 3 = 15
5 x 4 = 20
5 x 5 = 25
5 x 6 = 30
5 x 7 = 35
5 x 8 = 40
5 x 9 = 45
5 x 10 = 50

Q7. Program to find factorial with recursive function

def fact(i):
    if i-1 >= 0:
        return i * fact(i - 1)
    else:
        return 1

print(f"Factorial of 3 is {fact(3)}") # Find and Output Factorial of 3

Show Output

Factorial of 3 is 6

Verify: 3 * 2 * 1 = 6 ✅