disable 'dense' callback in py26

lib/ansible/plugins/callback/dense.py

@@ -21,7 +21,13 @@ __metaclass__ = type
 
 from ansible.plugins.callback.default import CallbackModule as CallbackModule_default
 from ansible.utils.color import colorize, hostcolor
-from collections import OrderedDict
+
+HAS_OD = False
+try:
+    from collections import OrderedDict
+    HAS_OD = True
+except ImportError:
+    pass
 
 try:
     from __main__ import display
@@ -153,6 +159,9 @@ class CallbackModule_dense(CallbackModule_default):
         # From CallbackModule
         self._display = display
 
+        if HAS_OD:
+
+            self.disabled = False
             self.super_ref = super(CallbackModule, self)
             self.super_ref.__init__()
 
@@ -179,6 +188,9 @@ class CallbackModule_dense(CallbackModule_default):
             # Start immediately on the first line
             sys.stdout.write(vt100.reset + vt100.save + vt100.clearline)
             sys.stdout.flush()
+        else:
+            display.warning("The 'dense' callback plugin requires OrderedDict which is not available in this version of python, disabling.")
+            self.disabled = True
 
     def __del__(self):
         sys.stdout.write(vt100.restore + vt100.reset + '\n' + vt100.save + vt100.clearline)
@@ -478,7 +490,7 @@ class CallbackModule_dense(CallbackModule_default):
             )
 
 # When using -vv or higher, simply do the default action
-if display.verbosity >= 2:
+if display.verbosity >= 2 or not HAS_OD:
     CallbackModule = CallbackModule_default
 else:
     CallbackModule = CallbackModule_dense