Switch to using a named LDAP tuple for more readable code

data/users.py

@@ -9,6 +9,7 @@ import os
 from util.aes import AESCipher
 from util.validation import generate_valid_usernames
 from data import model
+from collections import namedtuple
 
 logger = logging.getLogger(__name__)
 if os.environ.get('LDAP_DEBUG') == '1':
@@ -55,6 +56,8 @@ class LDAPConnection(object):
 
 
 class LDAPUsers(object):
+  _LDAPResult = namedtuple('LDAPResult', ['dn', 'attrs'])
+
   def __init__(self, ldap_uri, base_dn, admin_dn, admin_passwd, user_rdn, uid_attr, email_attr):
     self._ldap_conn = LDAPConnection(ldap_uri, admin_dn, admin_passwd)
     self._ldap_uri = ldap_uri
@@ -110,9 +113,11 @@ class LDAPUsers(object):
 
       logger.debug('Found matching pairs: %s', pairs)
 
+      results = [LDAPUsers._LDAPResult(*pair) for pair in pairs]
+
       # Filter out pairs without DNs. Some LDAP impls will return such
       # pairs.
-      with_dns = [pair for pair in pairs if pair[0]]
+      with_dns = [result for result in results if result.dn]
       if len(with_dns) < 1:
         return None
 
@@ -122,7 +127,7 @@ class LDAPUsers(object):
 
       # Otherwise, there are multiple pairs with DNs, so find the one with the mail
       # attribute (if any).
-      with_mail = [pair for pair in pairs if pair[1].get(self._email_attr)]
+      with_mail = [result for result in results if result.attrs.get(self._email_attr)]
       return with_mail[0] if with_mail else with_dns[0]
 
   def confirm_existing_user(self, username, password):