Overwrite vs append behavior in Python - Hands-On Comparison

Overwrite vs append behavior

📖 Scenario: Imagine you are keeping a simple log of daily tasks in a text file. Sometimes you want to replace the whole log with new tasks, and other times you want to add new tasks to the existing log without losing the old ones.

🎯 Goal: You will learn how to write to a file in Python using two different modes: overwrite and append. You will create a file with some tasks, then add more tasks without deleting the old ones, and finally replace all tasks with a new list.

📋 What You'll Learn

Create a text file with initial tasks using overwrite mode

Create a variable to hold new tasks to add

Append new tasks to the existing file without deleting old tasks

Overwrite the file with a completely new set of tasks

Print the final content of the file

💡 Why This Matters

🌍 Real World

File writing and appending is used in logging, saving user data, and updating records without losing previous information.

💼 Career

Knowing how to manage file content safely is essential for software developers, data analysts, and system administrators.

1

Create initial task list file with overwrite mode

Create a file called tasks.txt and write these exact tasks using overwrite mode: "Buy groceries\nClean the house\nPay bills\n". Use open with mode 'w' and write method.

Python

# Your code here

Need a hint?

Use open with mode 'w' to overwrite the file. Use write to add the tasks as a string with newline characters.

2

Create a variable with new tasks to add

Create a variable called new_tasks and set it to the string "Walk the dog\nRead a book\n".

Python

with open('tasks.txt', 'w') as file:
    file.write("Buy groceries\nClean the house\nPay bills\n")

# Your code here

Need a hint?

Just create a string variable with the new tasks separated by newline characters.

3

Append new tasks to the existing file

Open tasks.txt in append mode using open with mode 'a'. Use write to add the contents of new_tasks to the file without deleting existing tasks.

Python

with open('tasks.txt', 'w') as file:
    file.write("Buy groceries\nClean the house\nPay bills\n")

new_tasks = "Walk the dog\nRead a book\n"

# Your code here

Need a hint?

Use mode 'a' to add to the file without removing old content.

4

Overwrite the file with a new set of tasks and print the final content

Open tasks.txt in overwrite mode 'w' and write the string "Exercise\nCook dinner\n" to replace all tasks. Then open the file in read mode 'r' and print its content using print.

Python

with open('tasks.txt', 'w') as file:
    file.write("Buy groceries\nClean the house\nPay bills\n")

new_tasks = "Walk the dog\nRead a book\n"

with open('tasks.txt', 'a') as file:
    file.write(new_tasks)

# Your code here

Need a hint?

Use 'w' mode to overwrite the file. Then read and print the file content to see the final tasks.