Fixes for py2.6

IPython/nbconvert/filters/strings.py

@@ -19,6 +19,7 b' templates.'
 import re
 import textwrap
 from xml.etree import ElementTree
+from types import StringTypes
 
 from IPython.utils import py3compat
 
@@ -61,11 +62,7 b' def html_text(element):'
     
     Analog of jQuery's $(element).text()
     """
-    instance_element_tree = isinstance(ElementTree.ElementTree, type) and \
-                            isinstance(element, (ElementTree.ElementTree))
-    instance_element = isinstance(ElementTree.Element, type) and \
-                       isinstance(element, (ElementTree.Element))
-    if not (instance_element or instance_element_tree):
+    if isinstance(element, StringTypes):
         element = ElementTree.fromstring(element)
     
     text = element.text or ""

IPython/nbconvert/tests/base.py

@@ -18,6 +18,7 b' import subprocess'
 import os
 import glob
 import shutil
+import sys
 
 import IPython
 from IPython.utils.tempdir import TemporaryDirectory
@@ -166,5 +167,5 b' class TestsBase(object):'
 
 
     def call(self, parameters):
-        return subprocess.check_output(parameters)
+        return subprocess.Popen(parameters, stdout=subprocess.PIPE).communicate()[0]
      
  No newline at end of file