Changes to bonus exercise explaination

Author: Snowwpanda

30_introduction_data_exploration.ipynb

@@ -1365,7 +1365,13 @@
     "\n",
     "Note: You will need to restart the kernel after applying changes to the packages.\n",
     "\n",
-    "(If you are interested in a solution, we have a fixed version under `tutorial/my_bubbly.py`, feel free to check the differences.)"
+    "<details>\n",
+    "<summary><b>Hint</b> (click to reveal)</summary>\n",
+    "\n",
+    "The changes are all in the `make_grid` / `make_grid_with_categories` functions around lines 272, 282, 313, and 328.\n",
+    "The broken code uses a pandas method that was removed in newer versions.\n",
+    "\n",
+    "</details>"
    ]
   },
   {
@@ -1387,6 +1393,23 @@
     "    x_logscale=True, scale_bubble=3, height=650)\n",
     "iplot(figure, config={'scrollZoom': True})\n"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "If you are interested in a solution, we have a fixed version under `tutorial/my_bubbly.py`. You can compare the two files with Python's `difflib` module:\n",
+    "\n",
+    "```python\n",
+    "import difflib\n",
+    "with open('data/data_exploration/bubbly.py') as f:\n",
+    "    original = f.readlines()\n",
+    "with open('tutorial/my_bubbly.py') as f:\n",
+    "    fixed = f.readlines()\n",
+    "diff = difflib.unified_diff(original, fixed, fromfile='bubbly.py', tofile='my_bubbly.py')\n",
+    "print(''.join(diff))\n",
+    "```"
+   ]
   }
  ],
  "metadata": {