Improve users management on kfet TestCase, and Py34 compat

kfet/tests/testcases.py

@@ -5,6 +5,7 @@ from django.core.urlresolvers import reverse
 from django.http import QueryDict
 from django.test import Client
 from django.utils import timezone
+from django.utils.functional import cached_property
 
 from .utils import create_root, create_team, create_user
 
@@ -180,9 +181,9 @@ class ViewTestCaseMixin(TestCaseMixin):
     - 'root': a superuser, account trigramme: 200.
     Their password is their username.
 
-    One can create additionnal users with 'users_extra' attribute, or prevent
-    these 3 users to be created with 'users_base' attribute. See these two
-    properties for further informations.
+    One can create additionnal users with 'get_users_extra' method, or prevent
+    these 3 users to be created with 'get_users_base' method. See these two
+    methods for further informations.
 
     By using 'register_user' method, these users can then be accessed at
     'users' attribute by their label. Similarly, their kfet account is
@@ -240,7 +241,7 @@ class ViewTestCaseMixin(TestCaseMixin):
         self.users = {}
         self.accounts = {}
 
-        for label, user in {**self.users_base, **self.users_extra}.items():
+        for label, user in dict(self.users_base, **self.users_extra).items():
             self.register_user(label, user)
 
         if self.auth_user:
@@ -252,8 +253,20 @@ class ViewTestCaseMixin(TestCaseMixin):
                 )
             )
 
-    @property
-    def users_base(self):
+    def tearDown(self):
+        del self.users_base
+        del self.users_extra
+
+    def get_users_base(self):
+        """
+        Dict of <label: user instance>.
+
+        Note: Don't access yourself this property. Use 'users_base' attribute
+        which cache the returned value from here.
+        It allows to give functions calls, which creates users instances, as
+        values here.
+
+        """
         # Format desc: username, password, trigramme
         return {
             # user, user, 000
@@ -264,10 +277,26 @@ class ViewTestCaseMixin(TestCaseMixin):
             'root': create_root(),
         }
 
-    @property
-    def users_extra(self):
+    @cached_property
+    def users_base(self):
+        return self.get_users_base()
+
+    def get_users_extra(self):
+        """
+        Dict of <label: user instance>.
+
+        Note: Don't access yourself this property. Use 'users_base' attribute
+        which cache the returned value from here.
+        It allows to give functions calls, which create users instances, as
+        values here.
+
+        """
         return {}
 
+    @cached_property
+    def users_extra(self):
+        return self.get_users_extra()
+
     def register_user(self, label, user):
         self.users[label] = user
         if hasattr(user.profile, 'account_kfet'):