📊 Unit-IV: Python GUI Programming with Tkinter

Copy import tkinter as tk def button_click(event=None): print("Button was clicked!") label.config(text="Button Clicked!") def on_key_press(event): print(f"Key pressed: {event.char}") root = tk.Tk() # Button with command binding button = tk.Button(root, text="Click Me", command=button_click) button.pack(pady=10) # Binding to a specific key root.bind('', button_click) # Press Enter to trigger # Binding to all key presses root.bind('', on_key_press) # Label to show event results label = tk.Label(root, text="") label.pack(pady=10) root.mainloop()

Copy # Mouse events widget.bind('', callback) # Left mouse button widget.bind('', callback) # Double click widget.bind('', callback) # Left button drag widget.bind('', callback) # Mouse enters widget widget.bind('', callback) # Mouse leaves widget # Keyboard events widget.bind('', callback) # Any key press widget.bind('', callback) # Enter/Return key widget.bind('', callback) # Ctrl+C # Window events root.protocol('WM_DELETE_WINDOW', on_close) # Window close # Focus events widget.bind('', callback) # Widget gets focus widget.bind('', callback) # Widget loses focus

Copy import tkinter as tk from tkinter import messagebox def validate_number(input): if input.isdigit() or input == '': # Allow empty string for backspace return True elif input == '.': return True else: return False def on_submit(): if entry.get(): messagebox.showinfo("Success", f"You entered: {entry.get()}") root = tk.Tk() # Register the validation function vcmd = (root.register(validate_number), '%P') # Create and pack widgets label = tk.Label(root, text="Enter a number:") label.pack(pady=5) entry = tk.Entry( root, validate='key', validatecommand=vcmd ) entry.pack(pady=5) submit_btn = tk.Button(root, text="Submit", command=on_submit) submit_btn.pack(pady=10) root.mainloop()

Copy import tkinter as tk from tkinter import messagebox import sqlite3 from sqlite3 import Error def create_connection(): conn = None try: conn = sqlite3.connect('database.db') return conn except Error as e: print(e) return conn def create_table(conn): try: cursor = conn.cursor() cursor.execute(''' CREATE TABLE IF NOT EXISTS users ( id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, email TEXT UNIQUE NOT NULL, age INTEGER ) ''') conn.commit() except Error as e: print(e) def add_user(): name = name_entry.get() email = email_entry.get() age = age_entry.get() if not name or not email: messagebox.showerror("Error", "Name and email are required!") return try: conn = create_connection() cursor = conn.cursor() cursor.execute(''' INSERT INTO users (name, email, age) VALUES (?, ?, ?) ''', (name, email, age)) conn.commit() messagebox.showinfo("Success", "User added successfully!") clear_entries() display_users() except sqlite3.IntegrityError: messagebox.showerror("Error", "Email already exists!") except Error as e: messagebox.showerror("Error", str(e)) finally: if conn: conn.close() def display_users(): try: conn = create_connection() cursor = conn.cursor() cursor.execute("SELECT * FROM users") rows = cursor.fetchall() # Clear the listbox user_list.delete(0, tk.END) # Add column headers user_list.insert(tk.END, "ID\tName\tEmail\tAge") user_list.insert(tk.END, "-" * 40) # Add user data for row in rows: user_list.insert(tk.END, f"{row[0]}\t{row[1]}\t{row[2]}\t{row[3] if row[3] else 'N/A'}") except Error as e: messagebox.showerror("Error", str(e)) finally: if conn: conn.close() def clear_entries(): name_entry.delete(0, tk.END) email_entry.delete(0, tk.END) age_entry.delete(0, tk.END) # Create the main window root = tk.Tk() root.title("User Management System") root.geometry("600x400") # Create database and table if they don't exist conn = create_connection() if conn is not None: create_table(conn) conn.close() # Create and pack widgets tk.Label(root, text="Name:").pack(pady=5) name_entry = tk.Entry(root, width=40) name_entry.pack(pady=5) tk.Label(root, text="Email:").pack(pady=5) email_entry = tk.Entry(root, width=40) email_entry.pack(pady=5) tk.Label(root, text="Age:").pack(pady=5) age_entry = tk.Entry(root, width=10) age_entry.pack(pady=5) add_btn = tk.Button(root, text="Add User", command=add_user) add_btn.pack(pady=10) # Create a listbox to display users user_list = tk.Listbox(root, width=80, height=10) user_list.pack(pady=10) # Display existing users display_users() root.mainloop()

Copy # Create (Insert) def create_product(): # Get values from entries # Validate input # Insert into database # Refresh the view pass # Read (Select) def read_products(): # Query all products # Display in a listbox or treeview pass # Update def update_product(): # Get selected product ID # Get updated values # Update database # Refresh the view pass # Delete def delete_product(): # Get selected product ID # Confirm deletion # Delete from database # Refresh the view pass