Simple Login Application in Python Tutorial with Source Code

Submitted by razormist on Monday, January 4, 2021 - 10:28.

In this tutorial, we will create a Simple Login Application in Python. Python has a design philosophy that emphasizes code readability. That's why Python is very easy to use especially for beginners who just started programming. It is very easy to learn the syntax emphasizes readability and it can reduce time-consuming in developing. So let's now do the coding.

Getting started

First you will have to download & install the Python IDLE's, here's the link for the Integrated Development And Learning Environment for Python https://www.python.org/downloads/.

Installing SQLite Browser

After you installed Python, we will now then install the SQLite, here's the link for the DB Browser for SQLite http://sqlitebrowser.org/.

Importing Modules

After setting up the installation and the database, run the IDLE and click file and then new file. After that a new window will appear containing a black file this will be the text editor for the python.

Then copy the code that I provided below and paste it inside the IDLE text editor

from tkinter import *
import sqlite3

Setting up the Main Frame

After importing the modules, we will now then create the main frame for the application. To do that just copy the code below and paste it inside the IDLE text editor.

root = Tk()
root.title("Python: Simple Login Application")
width = 400
height = 280
screen_width = root.winfo_screenwidth()
screen_height = root.winfo_screenheight()
x = (screen_width/2) - (width/2)
y = (screen_height/2) - (height/2)
root.geometry("%dx%d+%d+%d" % (width, height, x, y))
root.resizable(0, 0)

Designing the Layout

After creating the Main Frame we will now add some layout to the application. Just kindly copy the code below and paste it inside the IDLE text editor.

#==============================VARIABLES======================================
USERNAME = StringVar()
PASSWORD = StringVar()
 
#==============================FRAMES=========================================
Top = Frame(root, bd=2,  relief=RIDGE)
Top.pack(side=TOP, fill=X)
Form = Frame(root, height=200)
Form.pack(side=TOP, pady=20)
 
#==============================LABELS=========================================
lbl_title = Label(Top, text = "Python: Simple Login Application", font=('arial', 15))
lbl_title.pack(fill=X)
lbl_username = Label(Form, text = "Username:", font=('arial', 14), bd=15)
lbl_username.grid(row=0, sticky="e")
lbl_password = Label(Form, text = "Password:", font=('arial', 14), bd=15)
lbl_password.grid(row=1, sticky="e")
lbl_text = Label(Form)
lbl_text.grid(row=2, columnspan=2)
 
#==============================ENTRY WIDGETS==================================
username = Entry(Form, textvariable=USERNAME, font=(14))
username.grid(row=0, column=1)
password = Entry(Form, textvariable=PASSWORD, show="*", font=(14))
password.grid(row=1, column=1)
 
#==============================BUTTON WIDGETS=================================
btn_login = Button(Form, text="Login", width=45, command=Login)
btn_login.grid(pady=25, row=3, columnspan=2)
btn_login.bind('<Return>', Login)

Creating the Database Connection

Then after setting up the design we will now create the database function. To do that just simply copy the code below and paste it inside the IDLE text editor

#==============================METHODS========================================
def Database():
    global conn, cursor
    conn = sqlite3.connect("pythontut.db")
    cursor = conn.cursor()
    cursor.execute("CREATE TABLE IF NOT EXISTS `member` (mem_id INTEGER NOT NULL PRIMARY KEY  AUTOINCREMENT, username TEXT, password TEXT)")       
    cursor.execute("SELECT * FROM `member` WHERE `username` = 'admin' AND `password` = 'admin'")
    if cursor.fetchone() is None:
        cursor.execute("INSERT INTO `member` (username, password) VALUES('admin', 'admin')")
        conn.commit()

Creating the Main Function

This is the main function where the Entry will be check if there is a user exist in the database, after login correctly a new window will pop up. To do that just simply copy the code below then paste it inside the IDLE text editor.

def Login(event=None):
    Database()
    if USERNAME.get() == "" or PASSWORD.get() == "":
        lbl_text.config(text="Please complete the required field!", fg="red")
    else:
        cursor.execute("SELECT * FROM `member` WHERE `username` = ? AND `password` = ?", (USERNAME.get(), PASSWORD.get()))
        if cursor.fetchone() is not None:
            HomeWindow()
            USERNAME.set("")
            PASSWORD.set("")
            lbl_text.config(text="")
        else:
            lbl_text.config(text="Invalid username or password", fg="red")
            USERNAME.set("")
            PASSWORD.set("")   
    cursor.close()
    conn.close()
 
def HomeWindow():
    global Home
    root.withdraw()
    Home = Toplevel()
    Home.title("Python: Simple Login Application")
    width = 600
    height = 500
    screen_width = root.winfo_screenwidth()
    screen_height = root.winfo_screenheight()
    x = (screen_width/2) - (width/2)
    y = (screen_height/2) - (height/2)
    root.resizable(0, 0)
    Home.geometry("%dx%d+%d+%d" % (width, height, x, y))
    lbl_home = Label(Home, text="Successfully Login!", font=('times new roman', 20)).pack()
    btn_back = Button(Home, text='Back', command=Back).pack(pady=20, fill=X)
 
def Back():
    Home.destroy()
    root.deiconify()

Initializing the Application

After finishing the function save the application as 'index.py'. This function will run the code and check if the main is initialize properly. To do that copy the code below and paste it inside the IDLE text editor.

#==============================INITIALIATION==================================
if __name__ == '__main__':
    root.mainloop()

There you have it we just created a Simple Login Application using Python. I hope that this simple tutorial helps you expand the idea of Python programming. For more updates and tutorials just kindly visit this site.

Enjoy Coding!!

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Comments

it

it help me a lot.

Hi kff, I'm glad that I could

Hi kff, I'm glad that I could help..

why is it the Login is

why is it the Login is undefined?

It is undefined probably because you defined "Login" after the command was binded to the button. Move the "def Login():" above the bind command

I need help with the login stage - i want to make multiple login

in the database connection stage i made a elif statement to save the values employee def Database(): global conn, cursor conn = sqlite3.connect("SCCSDatabase.db") cursor = conn.cursor() cursor.execute("CREATE TABLE IF NOT EXISTS `member` (mem_id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, username TEXT, password TEXT)") cursor.execute("CREATE TABLE IF NOT EXISTS `employee` (employee_id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, username1 TEXT, password1 TEXT)") cursor.execute("SELECT * FROM `member` WHERE `username` = 'admin' AND `password` = 'admin'") cursor.execute("SELECT * FROM `employee` WHERE `username1` = 'employee' AND `password1` = 'employee'") if cursor.fetchone() is None: cursor.execute("INSERT INTO `member` (username, password) VALUES('admin', 'admin')") conn.commit() elif cursor.fetchone() is None: cursor.execute("INSERT INTO `employee` (username1, password1) VALUES('employee', 'employee')") conn.commit() can you help me create another login with those values

from turtle import*
pensize(3)
clr=("blue","brown","red","green","orange","purple")
for i in clr:
 right(60)
 color(i)
 circle(90)