Update cheatsheet notebook

Author: edschofield

docs/notebooks/Writing Python 2-3 compatible code.ipynb

@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:c37888c8f9a1f8ba6d3693b55f121f2581ba744bc5feb6b9153a419891328945"
+  "signature": "sha256:5214500bd0fe36eb284cf7f699558f65c1ec6897953be31caaed9ee69aea1718"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -121,7 +121,8 @@
      "collapsed": false,
      "input": [
       "# Python 2 and 3:\n",
-      "from __future__ import print_function\n",
+      "from __future__ import print_function    # (at top of module)\n",
+      "\n",
       "print('Hello', 'Guido')"
      ],
      "language": "python",
@@ -144,7 +145,7 @@
      "collapsed": false,
      "input": [
       "# Python 2 and 3:\n",
-      "from __future__ import print_function    # (at top of module)\n",
+      "from __future__ import print_function\n",
       "\n",
       "print('Hello', file=sys.stderr)"
      ],
@@ -168,7 +169,7 @@
      "collapsed": false,
      "input": [
       "# Python 2 and 3:\n",
-      "from __future__ import print_function    # (at top of module)\n",
+      "from __future__ import print_function\n",
       "\n",
       "print('Hello', end='')"
      ],
@@ -206,35 +207,6 @@
      "metadata": {},
      "outputs": []
     },
-    {
-     "cell_type": "markdown",
-     "metadata": {},
-     "source": [
-      "Raising bare string exceptions:"
-     ]
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "# Python 2 only:\n",
-      "raise \"dodgy value\""
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "# Python 2 and 3:\n",
-      "raise Exception(\"dodgy value\")"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
     {
      "cell_type": "markdown",
      "metadata": {},
@@ -667,7 +639,7 @@
      "collapsed": false,
      "input": [
       "# Python 3 only:\n",
-      "class Form(metaclass=BaseForm):\n",
+      "class Form(BaseForm, metaclass=FormType):\n",
       "    pass"
      ],
      "language": "python",