help making a tk/msql user login

[Thekid]

I've decided to try and make a login window using tkinter that will connect to a mysql database if the proper username and password are entered. I can connect automatically if I have that info already in the script, but can't quite make it work if it's entered into entry fields. I was trying something like this:

from Tkinter import *
import sys
import MySQLdb


# Get the info entered in the root window entry fields
# and store them in variables f=(username), g=(password)
def SaveData():
    f = a.get()
    g = b.get()

    # try to connect to mysql and use entered info (f,g)
    try:
      conn = MySQLdb.connect (host = "localhost",
                              user = "%s",
                              passwd = "%s",
                              db = "maindb") % f,g
    except MySQLdb.Error, e:
      print "Error %d: %s" % (e.args[0], e.args[1])
      sys.exit (1)

    cursor = conn.cursor () 
     
root = Tk()
 
ent_frame = Frame(root)
Label(ent_frame, text="USERNAME:").pack(side=LEFT)
a = Entry(ent_frame, width=15)
a.pack(side=LEFT)
Label(ent_frame, text="PASSWORD:").pack(side=LEFT)
b = Entry(ent_frame, width=15)
b.pack(side=LEFT)
ent_frame.pack()
 
Button(root, text="Login",command=SaveData).pack(side=BOTTOM)

mainloop()

That's the basis of what I want and I've tried making the login information in a dictionary form first, then having it pass through conn = MySQLdb.connect but that fails as well. How can I properly format this so that the entered username and password will be used and not be hardcoded in the script?

Error 1045: Access denied for user '%s'@'localhost ' (using password: YES)

---that's the error message, obviously it's not replacing %s

[bvdet]

You are close. Your string formatting was not done properly. The modulo operator produces a formatted string given a format string and a collection of objects in a tuple or dictionary. Example:

>>> a = 123
>>> b = 456
>>> "Variables a and b are set to %s and %s respectively." % (a, b)
'Variables a and b are set to 123 and 456 respectively.'
>>>

So your code should be:

      conn = MySQLdb.connect (host = "localhost",
                              user = "%s" % (f),
                              passwd = "%s" % (g),
                              db = "maindb")

[Thekid]

Oh, I see. So close :) Thanks.