GUI-todo-list.py

import tkinter as tk
from tkinter import ttk
from tkinter import messagebox
import sqlite3 as sq
    
root = tk.Tk()
root.title('To-Do List')
root.geometry("400x250+500+300")
    
conn = sq.connect('todo.db')
cur = conn.cursor()
cur.execute('create table if not exists tasks (title text)')
   
task = []
    #------------------------------- Functions--------------------------------
def addTask():
    word = e1.get()
    if len(word)==0:
        messagebox.showinfo('Empty Entry', 'Enter task name')
    else:
        task.append(word)
        cur.execute('insert into tasks values (?)', (word,))
        listUpdate()
        e1.delete(0,'end')
    
def listUpdate():
    clearList()
    for i in task:
        t.insert('end', i)
    
def delOne():
    try:
        val = t.get(t.curselection())
        if val in task:
            task.remove(val)
            listUpdate()
            cur.execute('delete from tasks where title = ?', (val,))
    except:
        messagebox.showinfo('Cannot Delete', 'No Task Item Selected')
        
def deleteAll():
    mb = messagebox.askyesno('Delete All','Are you sure?')
    if mb==True:
        while(len(task)!=0):
            task.pop()
            cur.execute('delete from tasks')
            listUpdate()
    
def clearList():
    t.delete(0,'end')
    
def bye():
    print(task)
    root.destroy()
    
def retrieveDB():
    while(len(task)!=0):
        task.pop()
    for row in cur.execute('select title from tasks'):
        task.append(row[0])
          
    #------------------------------- Functions--------------------------------
    
l1 = ttk.Label(root, text = 'To-Do List')
l2 = ttk.Label(root, text='Enter task title: ')
e1 = ttk.Entry(root, width=21)
t = tk.Listbox(root, height=11, selectmode='SINGLE')
b1 = ttk.Button(root, text='Add task', width=20, command=addTask)
b2 = ttk.Button(root, text='Delete', width=20, command=delOne)
b3 = ttk.Button(root, text='Delete all', width=20, command=deleteAll)
b4 = ttk.Button(root, text='Exit', width=20, command=bye)
    
retrieveDB()
listUpdate()

#Place geometry
l2.place(x=50, y=50)
e1.place(x=50, y=80)
b1.place(x=50, y=110)
b2.place(x=50, y=140)
b3.place(x=50, y=170)
b4.place(x=50, y =200)
l1.place(x=50, y=10)
t.place(x=220, y = 50)
root.mainloop()

conn.commit()
cur.close()