13 – Real-World Python Projects – To-Do List App

🎯 Project Objective

To build a To-Do List Application in Python that allows users to add, edit, delete, and mark tasks as completed with a simple and intuitive GUI.

Skills Demonstrated:

Tkinter GUI development
File handling (CSV/JSON)
Event handling and widget manipulation
Persistent data storage

Project Description

The To-Do List App lets users:

Add daily tasks
Mark tasks as done or pending
Delete completed tasks
Save and load tasks automatically

Use Cases:

Personal productivity tool
Student homework tracker
Daily goal planner

🧩 Example Code – To-Do List GUI App (Tkinter)

import tkinter as tk
from tkinter import messagebox
import json
import os

# File to store tasks
TASK_FILE = "tasks.json"

# Load existing tasks
if os.path.exists(TASK_FILE):
    with open(TASK_FILE, "r") as f:
        tasks = json.load(f)
else:
    tasks = []

# Save tasks to file
def save_tasks():
    with open(TASK_FILE, "w") as f:
        json.dump(tasks, f)

# Add new task
def add_task():
    task = entry_task.get().strip()
    if task:
        tasks.append({"task": task, "done": False})
        update_listbox()
        save_tasks()
        entry_task.delete(0, tk.END)
    else:
        messagebox.showwarning("Warning", "Please enter a task!")

# Delete selected task
def delete_task():
    selected = listbox_tasks.curselection()
    if selected:
        index = selected[0]
        tasks.pop(index)
        update_listbox()
        save_tasks()
    else:
        messagebox.showwarning("Warning", "Select a task to delete!")

# Mark task as done
def mark_done():
    selected = listbox_tasks.curselection()
    if selected:
        index = selected[0]
        tasks[index]["done"] = True
        update_listbox()
        save_tasks()
    else:
        messagebox.showwarning("Warning", "Select a task to mark as done!")

# Update listbox display
def update_listbox():
    listbox_tasks.delete(0, tk.END)
    for i, task in enumerate(tasks):
        status = "✅" if task["done"] else "❌"
        listbox_tasks.insert(tk.END, f"{status} {task['task']}")

# GUI setup
root = tk.Tk()
root.title("To-Do List App")
root.geometry("400x400")

tk.Label(root, text="Enter a new task:", font=("Arial", 12)).pack(pady=5)
entry_task = tk.Entry(root, width=35)
entry_task.pack(pady=5)

# Buttons
frame_buttons = tk.Frame(root)
frame_buttons.pack(pady=10)

tk.Button(frame_buttons, text="Add Task", command=add_task).grid(row=0, column=0, padx=5)
tk.Button(frame_buttons, text="Mark Done", command=mark_done).grid(row=0, column=1, padx=5)
tk.Button(frame_buttons, text="Delete Task", command=delete_task).grid(row=0, column=2, padx=5)

# Task list display
listbox_tasks = tk.Listbox(root, width=50, height=15)
listbox_tasks.pack(pady=10)

update_listbox()
root.mainloop()

✅ Output

A GUI window with:

Text entry field to add new tasks
Listbox showing tasks with ✅ (done) or ❌ (pending)
Buttons to add, delete, and mark tasks
Automatic save and load from tasks.json

✅ Key Features

Extensible for more advanced features

Simple, user-friendly GUI

Task management (add, delete, mark done)

Persistent storage (JSON file)

Status tracking with visual indicators