Fix modelchain_example notebook

Author: SabineHaas

example/modelchain_example.ipynb

@@ -121,18 +121,17 @@
     "        kwargs['datapath'] = os.path.join(os.path.split(\n",
     "            os.path.dirname(__file__))[0], 'example')\n",
     "    file = os.path.join(kwargs['datapath'], filename)\n",
-    "    # read csv file \n",
+    "    # read csv file\n",
     "    weather_df = pd.read_csv(\n",
     "        file, index_col=0, header=[0, 1],\n",
     "        date_parser=lambda idx: pd.to_datetime(idx, utc=True))\n",
     "    # change type of index to datetime and set time zone\n",
     "    weather_df.index = pd.to_datetime(weather_df.index).tz_convert(\n",
     "        'Europe/Berlin')\n",
     "    # change type of height from str to int by resetting columns\n",
-    "    weather_df.columns = [weather_df.axes[1].levels[0][\n",
-    "                              weather_df.axes[1].codes[0]],\n",
-    "                          weather_df.axes[1].levels[1][\n",
-    "                              weather_df.axes[1].codes[1]].astype(int)]\n",
+    "    l0 = [_[0] for _ in weather_df.columns]\n",
+    "    l1 = [int(_[1]) for _ in weather_df.columns]\n",
+    "    weather_df.columns = [l0, l1]\n",
     "    return weather_df\n",
     "\n",
     "\n",