diff --git a/rest_framework/versioning.py b/rest_framework/versioning.py
index 751df5be5..c6df091d5 100644
--- a/rest_framework/versioning.py
+++ b/rest_framework/versioning.py
@@ -135,11 +135,12 @@ class NamespaceVersioning(BaseVersioning):
         )
 
     def get_versioned_viewname(self, viewname, request):
-        if not ":" in viewname:
+        if ":" not in viewname:
             return request.version + ":" + viewname
         else:
             return viewname
 
+
 class HostNameVersioning(BaseVersioning):
     """
     GET /something/ HTTP/1.1