import tkinter as tk
root = tk.Tk()

import sqlite3
conn = sqlite3.connect("logins.db")
c = conn.cursor()

def login():
    dbuser = ""
    dbpass = ""

    l1 = tk.Label(root, text="Username:").grid(row=0)
    l2 = tk.Label(root, text="Password:").grid(row=1)
    userentry = tk.Entry(root).grid(row=0, column=1)
    userpass = tk.Entry(root).grid(row=1, column=1)
    sub = tk.Button(root, text="Submit", command=root.quit).grid(row=2)
    root.mainloop()

    username = userentry.get()
    password = userpass.get()

    print(username,password)

    while dbuser != username and dbpass != password:
        c.execute("SELECT * FROM logins WHERE Username=? AND Password=?", (username, password))
        a = c.fetchall()
        dbuser, dbpass = a[0]
    print("Logged in!")

login()