Fix 'Custom Display Logic' example notebook for Python 3

IPython/core/display.py

@@ -28,6 +28,8 b' from .displaypub import ('
     publish_javascript, publish_jpeg
 )
 
+from IPython.utils.py3compat import string_types
+
 #-----------------------------------------------------------------------------
 # Main functions
 #-----------------------------------------------------------------------------
@@ -254,7 +256,7 b' class DisplayObject(object):'
         filename : unicode
             Path to a local file to load the data from.
         """
-        if data is not None and data.startswith('http'):
+        if data is not None and isinstance(data, string_types) and data.startswith('http'):
             self.url = data
             self.filename = None
             self.data = None
@@ -475,7 +477,7 b' class Image(DisplayObject):'
             ext = self._find_ext(url)
         elif data is None:
             raise ValueError("No image data found. Expecting filename, url, or data.")
-        elif data.startswith('http'):
+        elif isinstance(data, string_types) and data.startswith('http'):
             ext = self._find_ext(data)
         else:
             ext = None

IPython/utils/py3compat.py

@@ -62,6 +62,8 b' if sys.version_info[0] >= 3:'
     bytes_to_str = decode
     cast_bytes_py2 = no_code
     
+    string_types = (str,)
+    
     def isidentifier(s, dotted=False):
         if dotted:
             return all(isidentifier(a) for a in s.split("."))
@@ -110,6 +112,8 b' else:'
     bytes_to_str = no_code
     cast_bytes_py2 = cast_bytes
     
+    string_types = (str, unicode)
+    
     import re
     _name_re = re.compile(r"[a-zA-Z_][a-zA-Z0-9_]*$")
     def isidentifier(s, dotted=False):

examples/notebooks/Custom Display Logic.ipynb

@@ -143,7 +143,7 b''
       "\n",
       "    def _repr_svg_(self):\n",
       "        if self._svg_data is None:\n",
-      "            self._svg_data = self._figure_data('svg')\n",
+      "            self._svg_data = self._figure_data('svg').decode('utf-8')\n",
       "        return self._svg_data\n",
       "    \n",
       "    def _repr_latex_(self):\n",
@@ -162,7 +162,7 b''
       "        \n",
       "    @property\n",
       "    def latex(self):\n",
-      "        return Math(self._repr_svg_())\n",
+      "        return Math(self._repr_latex_())\n",
       "    \n",
       "    # An example of using a property to display rich information, in this case\n",
       "    # the histogram of the distribution.  We've hardcoded the format to be png\n",