looping through a file

[Psybar Phreak]

hi all - ive just started with python (after having done java and c) and am
having a little bit of trouble with the script.  Im using as a login script.

There's a users.dat file in the format
user1
user1password
user2
user2password
... etc

at the moment - the code i work, only checks the first and second lines (ie.
details of user1).  but it appears that python doesn't have a do... while...
until loop.


can anyone help?

thanks!!

Ive attached the appropriate part of the code i have working

-------------------------------

#!/usr/local/bin/python

import cgi, string

form = cgi.FieldStorage()

if form.has_key('usernameField') and form.has_key('passwordField'):
         users_username = string.strip(form['usernameField'].value)
         users_password = string.strip(form['passwordField'].value)

InFile = open('users.dat', 'r')

file_username = string.strip(InFile.readline())
file_password = string.strip(InFile.readline())




authorised = 0

while file_username and file_password:
       if file_username == users_username:
              if file_password == users_password: # correct
             authorised = 1
      break
              else:                               # login matched but not
password
                    file_username = InFile.readline()
             file_password = InFile.readline()
       else: # neither match
              file_username = InFile.readline()
              file_password = InFile.readline()