Task List GUI App in Python

A Task List GUI (Graphical User Interface) app in Python is a simple yet powerful project ideal for managing personal tasks efficiently. Below is a complete implementation using tkinter, Python’s built-in GUI toolkit. This app allows users to add, delete, and mark tasks as done, with a clean interface and persistent storage using a text file.

python
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import tkinter as tk
from tkinter import messagebox
import os

class TaskListApp:
    def __init__(self, root):
        self.root = root
        self.root.title("Task List App")
        self.root.geometry("400x500")
        self.root.resizable(False, False)

        self.task_file = "tasks.txt"
        self.tasks = []

        self.create_widgets()
        self.load_tasks()

    def create_widgets(self):
        self.frame = tk.Frame(self.root)
        self.frame.pack(pady=10)

        self.task_entry = tk.Entry(self.frame, width=30, font=("Arial", 14))
        self.task_entry.grid(row=0, column=0, padx=10)

        self.add_button = tk.Button(self.frame, text="Add Task", width=10, command=self.add_task)
        self.add_button.grid(row=0, column=1)

        self.task_listbox = tk.Listbox(self.root, height=20, width=45, font=("Arial", 12), selectbackground="lightblue")
        self.task_listbox.pack(pady=20)

        self.button_frame = tk.Frame(self.root)
        self.button_frame.pack()

        self.delete_button = tk.Button(self.button_frame, text="Delete Task", command=self.delete_task)
        self.delete_button.grid(row=0, column=0, padx=10)

        self.mark_done_button = tk.Button(self.button_frame, text="Mark as Done", command=self.mark_task_done)
        self.mark_done_button.grid(row=0, column=1, padx=10)

        self.clear_all_button = tk.Button(self.button_frame, text="Clear All", command=self.clear_all_tasks)
        self.clear_all_button.grid(row=0, column=2, padx=10)

    def add_task(self):
        task = self.task_entry.get().strip()
        if task:
            self.tasks.append(task)
            self.task_listbox.insert(tk.END, task)
            self.task_entry.delete(0, tk.END)
            self.save_tasks()
        else:
            messagebox.showwarning("Input Error", "Please enter a task.")

    def delete_task(self):
        try:
            selected_index = self.task_listbox.curselection()[0]
            task = self.task_listbox.get(selected_index)
            self.task_listbox.delete(selected_index)
            self.tasks.remove(task)
            self.save_tasks()
        except IndexError:
            messagebox.showwarning("Selection Error", "Please select a task to delete.")

    def mark_task_done(self):
        try:
            selected_index = self.task_listbox.curselection()[0]
            task = self.task_listbox.get(selected_index)
            if not task.startswith("[Done] "):
                task = "[Done] " + task
                self.tasks[selected_index] = task
                self.task_listbox.delete(selected_index)
                self.task_listbox.insert(selected_index, task)
                self.save_tasks()
        except IndexError:
            messagebox.showwarning("Selection Error", "Please select a task to mark as done.")

    def clear_all_tasks(self):
        confirm = messagebox.askyesno("Clear All", "Are you sure you want to clear all tasks?")
        if confirm:
            self.task_listbox.delete(0, tk.END)
            self.tasks.clear()
            self.save_tasks()

    def load_tasks(self):
        if os.path.exists(self.task_file):
            with open(self.task_file, "r") as file:
                for line in file:
                    task = line.strip()
                    if task:
                        self.tasks.append(task)
                        self.task_listbox.insert(tk.END, task)

    def save_tasks(self):
        with open(self.task_file, "w") as file:
            for task in self.tasks:
                file.write(task + "n")

if __name__ == "__main__":
    root = tk.Tk()
    app = TaskListApp(root)
    root.mainloop()

Features:

• Add Task: Users can input a new task using the entry box and add it to the list.

• Delete Task: Selected tasks can be removed from the list.

• Mark as Done: A selected task is prefixed with [Done] to indicate completion.

• Clear All: Deletes all tasks after confirmation.

• Persistent Storage: Tasks are stored in a tasks.txt file and automatically loaded on startup.

Requirements:

• Python 3.x

• No external libraries are needed since it uses tkinter, which comes with Python.

Customization Ideas:

• Add deadlines or priorities.

• Integrate calendar functionality.

• Export task list to CSV.

• Add dark mode or theme toggling.

This GUI app is an ideal beginner-to-intermediate project to learn Python GUI programming, file handling, and application design.