Added snippet for generator expressions.

core/functions.ipynb

@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:a81c81558508aed1c6f336342652e5f8dcc250ecd9f9f955b9e6e02d65a45c5c"
+  "signature": "sha256:d9c538ef6dad540e5963356ed91d625e86a9a447c42edc8d3fe3a76031768782"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -452,8 +452,8 @@
      "collapsed": false,
      "input": [
       "def squares(n=5):\n",
-      "    for i in xrange(1, n + 1):\n",
-      "        yield i ** 2\n",
+      "    for x in xrange(1, n + 1):\n",
+      "        yield x ** 2\n",
       "\n",
       "# No code is executed\n",
       "gen = squares()\n",
@@ -478,6 +478,40 @@
       }
      ],
      "prompt_number": 10
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "## Generator Expressions\n",
+      "\n",
+      "A generator expression is analogous to a comprehension.  A list comprehension is enclosed by [], a generator expression is enclosed by ():"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "gen = (x ** 2 for x in xrange(1, 6))\n",
+      "for x in gen:\n",
+      "    print x"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "1\n",
+        "4\n",
+        "9\n",
+        "16\n",
+        "25\n"
+       ]
+      }
+     ],
+     "prompt_number": 11
     }
    ],
    "metadata": {}