import ldap
from sets import Set

config = {'host': 'ldap://ldap.example.com', 'base': 'ou=People,dc=example,dc=com', 'attr': 'l'}

data = Set()

result = ldap.initialize(config['host']).search_s(config['base'], ldap.SCOPE_SUBTREE, '(%s=*)' % config['attr'], [ config['attr'] ] )

for dn, entry in result:
        for l in entry['l']:
                data.add(l)

for i in sorted(data):
        print i