Chapter 4 Modules ,Working with files, Exception handling

 - What is regEx? give example.

import re

# Regular Expression Example

pattern = re.compile(r'\b\d{3}-\d{2}-\d{4}\b')  # Matches social security numbers

text = "John's SSN is 123-45-6789."

match = pattern.search(text)

if match:

    print("SSN found:", match.group())

else:

    print("No SSN found.")

- What is user defined Module? Give example.

# User-Defined Module Example

# Save this code in a file named mymodule.py

def greet(name):

    return f"Hello, {name}!"

# In another script, you can use this module

import mymodule

message = mymodule.greet("Alice")

print(message)

 -What is the use of seek( ) & tell ( ) functions?

seek(offset, whence): Moves the file cursor to the specified offset position, relative to whence (0 for the beginning, 1 for the current position, and 2 for the end).

tell(): Returns the current position of the file cursor.

Write a short note on exception handling.

Exception Handling:

Exception handling in Python allows you to deal with errors or exceptions that may occur during the execution of a program. It involves the use of try, except, else, and finally blocks.

try:

    result = 10 / 0

except ZeroDivisionError:

    print("Cannot divide by zero!")

else:

    print(f"Result: {result}")

finally:

    print("This block always executes.")

 -What is a module? What is package? Explain with example.

Module: A module in Python is a file containing Python definitions and statements. It allows you to logically organize your Python code. For example:

# mymodule.py

def greet(name):

    return f"Hello, {name}!"

# main.py

import mymodule

print(mymodule.greet("Alice"))  # Output: Hello, Alice!

Package: A package is a way of organizing related modules into a single directory hierarchy. It helps in organizing the code and avoids naming conflicts. A package contains an __init__.py file and can have subpackages. Example:

mypackage/

├── __init__.py

├── module1.py

└── module2.py

 Explain any 2 functions in time module.

 --What are the types of file in Python?

- Write the use of seek & tell function.

- How to handle exception in Python?

-Explain any 2 metacharacters used in regular expression.