X-Git-Url: https://osm.etsi.org/gitweb/?a=blobdiff_plain;f=juju%2Ftag.py;h=25142293141ca15eb390af5a15a0dafa91acd362;hb=refs%2Ftags%2F0.4.0;hp=f10c5efe951a7c52f8075938ea34d7c8ad04187b;hpb=6ba2856fecf224ae3fd589331e889a6587e8153b;p=osm%2FN2VC.git

diff --git a/juju/tag.py b/juju/tag.py
index f10c5ef..2514229 100644
--- a/juju/tag.py
+++ b/juju/tag.py
@@ -1,11 +1,11 @@
 def _prefix(prefix, s):
-    if not s.startswith(prefix):
+    if s and not s.startswith(prefix):
         return '{}{}'.format(prefix, s)
     return s
 
 
 def untag(prefix, s):
-    if s.startswith(prefix):
+    if s and s.startswith(prefix):
         return s[len(prefix):]
     return s
 
@@ -21,3 +21,11 @@ def credential(cloud, user, credential_name):
 
 def model(cloud_name):
     return _prefix('model-', cloud_name)
+
+
+def user(username):
+    return _prefix('user-', username)
+
+
+def application(app_name):
+    return _prefix('application-', app_name)