fix iteritems for python3 compat

doc/ext/plot_directive.py

@@ -132,6 +132,14 @@ except ImportError:
     def format_template(template, **kw):
         return jinja.from_string(template, **kw)
 
+# Python2/3 compatibility
+import sys
+PY2 = sys.version_info[0] == 2
+if PY2:
+    iteritems = lambda d: d.iteritems()
+else:
+    iteritems = lambda d: d.items()
+
 import matplotlib
 import matplotlib.cbook as cbook
 matplotlib.use('Agg')
@@ -234,7 +242,7 @@ def mark_plot_labels(app, document):
     the "htmlonly" (or "latexonly") node to the actual figure node
     itself.
     """
-    for name, explicit in document.nametypes.iteritems():
+    for name, explicit in iteritems(document.nametypes):
         if not explicit:
             continue
         labelid = document.nameids[name]