Merge branch 'part4-sets'

Fixes #22

Author: macro1

part-4.ipynb

@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:826b0e4b3d39f844b868b8370fcaac110d06dbe6afb167b149a60d16aea5592e"
+  "signature": "sha256:57da39b42fe7452dcc70302cd9a783c3a0c4c707ecf5977e607f1ed08f3b755f"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -396,7 +396,9 @@
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "**Extra Credit:** Try using a list comprehension in the translate function."
+      "**Extra Credit:** Try using a list comprehension in the translate function.\n",
+      "\n",
+      "**Note:** Typing out the exercises for the next section, \"Sets\",  is optional. If your brain is melting, feel free to sit back, relax, and enjoy the rest of the lecture."
      ]
     },
     {
@@ -554,14 +556,6 @@
      "language": "python",
      "metadata": {},
      "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
     }
    ],
    "metadata": {}