#! /usr/bin/python
import posix
from string import splitfields
def userinfo(filename):
 """
 This function returns the list of users
 and a table containing users and their passwords
 """
 users, table = [], {}
 file = open(filename, 'r')
 for line in file.readlines():
 [name, password] = splitfields(line, ':')[:2]
 users.append(name)
 table[name] = password
 return users, table
def main():
 for filename in ('/etc/passwd', 'etc/passwd.bak'):
 try:
 users, table = userinfo(filename)
 print table.keys()[3:7], table['postgres']
 posix.system('ls -al ' + filename)
 except:
 print 'File "' + filename + '" not found!'
main()
q.execute('''
 select * from
 foo,bar,baz
 where
 foo.blah=bar.blah
 and baz.spam="eggs"
 ''')