Part 1 — Definition

File handling is an important part of any application. Python has several functions for creating, reading, updating, and deleting files. Using the with statement is the best practice as it automatically closes the file after the block of code is finished.

Part 2 — Syntax

with open("file.txt", "w") as f:
    f.write("Hello World")

with open("file.txt", "r") as f:
    content = f.read()

Part 3 — Example

Problem: Create a log file and add a timestamped entry.

import datetime

with open("log.txt", "a") as f:
    now = datetime.datetime.now()
    f.write(f"Access at {now}\n")

print("Log updated.")

Observation: The "a" mode stands for Append, which adds text to the end of the file without deleting the existing content.

Part 4 — Video

Video: Coming Soon

Part 1 — Definition

An **Exception** is an event that occurs during the execution of a program that disrupts the normal flow of instructions. Python uses the try-except block to "catch" these events and handle them so the program can continue.

Part 2 — Syntax

try:
    # Code that might fail
except ErrorType:
    # Code to handle failure
finally:
    # Always runs

Part 3 — Example

Problem: Handle a "Division by Zero" error.

try:
    num = int(input("Enter number: "))
    result = 100 / num
except ZeroDivisionError:
    print("Cannot divide by zero!")
except ValueError:
    print("Please enter a valid number.")
else:
    print(f"Result is {result}")

Part 4 — Video

Video: Coming Soon