counting nan rows

tutorials/things_in_pandas.ipynb

@@ -29,7 +29,7 @@
        "output_type": "stream",
        "stream": "stdout",
        "text": [
-        "Sebastian Raschka 25/01/2015 \n",
+        "Sebastian Raschka 28/01/2015 \n",
         "\n",
         "CPython 3.4.2\n",
         "IPython 2.3.1\n",
@@ -90,6 +90,7 @@
       "    - [Changing Values in a Column](#Changing-Values-in-a-Column)\n",
       "    - [Adding a New Column](#Adding-a-New-Column)\n",
       "- [Missing Values aka NaNs](#Missing-Values-aka-NaNs)\n",
+      "    - [Counting Rows with NaNs](#Counting-Rows-with-NaNs)\n",
       "    - [Selecting NaN Rows](#Selecting-NaN-Rows)\n",
       "    - [Selecting non-NaN Rows](#Selecting-non-NaN-Rows)\n",
       "    - [Filling NaN Rows](#Filling-NaN-Rows)\n",
@@ -937,6 +938,43 @@
       "<br>"
      ]
     },
+    {
+     "cell_type": "heading",
+     "level": 3,
+     "metadata": {},
+     "source": [
+      "Counting Rows with NaNs"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "nans = df.shape[0] - df.dropna().shape[0]\n",
+      "\n",
+      "print('%d rows have missing values' % nans)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "3 rows have missing values\n"
+       ]
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "<br>\n",
+      "<br>"
+     ]
+    },
     {
      "cell_type": "heading",
      "level": 3,