title: Issue with username and password variables in sqlite3 and tkinter
body: <p>I need my program to take the inputs from the entry fields in the Tkinter window and run them through the database to log the user in, however, it says that I have a binding problem with my parameter 0 (username), and I assume this would also occur with my password variable aswell.</p>
  
  <pre class="lang-py prettyprint-override"><code>def loginfunc():
          while True:
              with sqlite3.connect('MyComputerScience.db') as db:
                  cursor = db.cursor()
              find_user = ("SELECT * FROM users WHERE username = ? AND password = ?")
              cursor.execute(find_user, (username, password))
              results = cursor.fetchall()
              if results:
                  for i in results:
                      print ("welcome "+i[1]+"")
                      break
              else:
                  print ("Username or password incorrect")
                  login()
              break
  </code></pre>
  
  <pre class="lang-py prettyprint-override"><code>def login():
          screen1 = Toplevel(screen)
          screen1.title("Login")
          screen1.geometry("300x250")
  
          global username
          global password
          username = StringVar()
          password = StringVar()
  
          Label(screen1, text = "Please enter your username and password below: ").pack()
          Label(screen1, text = "").pack()
          Label(screen1, text = "Username: ").pack()
          Entry(screen1, textvariable = username).pack()
          Label(screen1, text = "").pack()
          Label(screen1, text = "Password: ").pack()
          Entry(screen1, textvariable = password).pack()
          Label(screen1, text = "").pack()
          Button(screen1, text = "Login", width = 10, height = 1, command=loginfunc).pack()
  </code></pre>
  
  <pre class="lang-py prettyprint-override"><code>File "C:\Users\notmyname\Desktop\NEA PROPER.py", line 90, in loginfunc
       cursor.execute(find_user, (username, password))
       sqlite3.InterfaceError: Error binding parameter 0 - probably unsupported type.
  </code></pre>