diff --git a/module3/exo3/exercice.ipynb b/module3/exo3/exercice.ipynb
index bc8660e04d86b78e18a4135530eb24e8f04ee95f..3b055bbf99123866d3ab94547aee33d155276e48 100644
--- a/module3/exo3/exercice.ipynb
+++ b/module3/exo3/exercice.ipynb
@@ -33,16 +33,463 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# Fichier source des données brutes au 20/08/2020\n",
+    "# Fichier source des données brutes au 20/08/2020 (mise à jour mensuelle)\n",
+    "# dans le dossier /work/module3/exo3/monthly_in_situ_co2_mlo_20200820.csv\n",
+    "# @see https://scrippsco2.ucsd.edu/data/atmospheric_co2/primary_mlo_co2_record.html\n",
     "raw_data = \"monthly_in_situ_co2_mlo_20200820.csv\""
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [],
-   "source": []
+   "source": [
+    "# https://pandas.pydata.org\n",
+    "# Version 0.22.0 (December 29, 2017) sur ce Jupyter !\n",
+    "import pandas as pd\n",
+    "\n",
+    "# print(pd.__version__) # La version de Pandas actuelle\n",
+    "# pd.show_versions() # Toutes les extensions installées\n",
+    "\n",
+    "# Lecture du fichier CSV et saut à la ligne 55 pour ignorer les commentaires\n",
+    "# Ce fichier possède 10 colonnes séparées par des virgules : \n",
+    "# - colonnes 1-4 : dates en plusieurs formats : Yr, Mn, Date, Date\n",
+    "# - colonnes 5-10 : mesures en ppm, si absente valeur par défaut = '-99.99'\n",
+    "data = pd.read_csv(raw_data, skiprows = 54)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/html": [
+       "<div>\n",
+       "<style scoped>\n",
+       "    .dataframe tbody tr th:only-of-type {\n",
+       "        vertical-align: middle;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe tbody tr th {\n",
+       "        vertical-align: top;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe thead th {\n",
+       "        text-align: right;\n",
+       "    }\n",
+       "</style>\n",
+       "<table border=\"1\" class=\"dataframe\">\n",
+       "  <thead>\n",
+       "    <tr style=\"text-align: right;\">\n",
+       "      <th></th>\n",
+       "      <th>Yr</th>\n",
+       "      <th>Mn</th>\n",
+       "      <th>Date</th>\n",
+       "      <th>Date</th>\n",
+       "      <th>CO2</th>\n",
+       "      <th>seasonally</th>\n",
+       "      <th>fit</th>\n",
+       "      <th>seasonally</th>\n",
+       "      <th>CO2</th>\n",
+       "      <th>seasonally</th>\n",
+       "    </tr>\n",
+       "  </thead>\n",
+       "  <tbody>\n",
+       "    <tr>\n",
+       "      <th>0</th>\n",
+       "      <td></td>\n",
+       "      <td></td>\n",
+       "      <td></td>\n",
+       "      <td></td>\n",
+       "      <td></td>\n",
+       "      <td>adjusted</td>\n",
+       "      <td></td>\n",
+       "      <td>adjusted fit</td>\n",
+       "      <td>filled</td>\n",
+       "      <td>adjusted filled</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>1</th>\n",
+       "      <td></td>\n",
+       "      <td></td>\n",
+       "      <td>Excel</td>\n",
+       "      <td></td>\n",
+       "      <td>[ppm]</td>\n",
+       "      <td>[ppm]</td>\n",
+       "      <td>[ppm]</td>\n",
+       "      <td>[ppm]</td>\n",
+       "      <td>[ppm]</td>\n",
+       "      <td>[ppm]</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>2</th>\n",
+       "      <td>1958</td>\n",
+       "      <td>01</td>\n",
+       "      <td>21200</td>\n",
+       "      <td>1958.0411</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>3</th>\n",
+       "      <td>1958</td>\n",
+       "      <td>02</td>\n",
+       "      <td>21231</td>\n",
+       "      <td>1958.1260</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>4</th>\n",
+       "      <td>1958</td>\n",
+       "      <td>03</td>\n",
+       "      <td>21259</td>\n",
+       "      <td>1958.2027</td>\n",
+       "      <td>315.70</td>\n",
+       "      <td>314.44</td>\n",
+       "      <td>316.19</td>\n",
+       "      <td>314.91</td>\n",
+       "      <td>315.70</td>\n",
+       "      <td>314.44</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>5</th>\n",
+       "      <td>1958</td>\n",
+       "      <td>04</td>\n",
+       "      <td>21290</td>\n",
+       "      <td>1958.2877</td>\n",
+       "      <td>317.45</td>\n",
+       "      <td>315.16</td>\n",
+       "      <td>317.30</td>\n",
+       "      <td>314.99</td>\n",
+       "      <td>317.45</td>\n",
+       "      <td>315.16</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>6</th>\n",
+       "      <td>1958</td>\n",
+       "      <td>05</td>\n",
+       "      <td>21320</td>\n",
+       "      <td>1958.3699</td>\n",
+       "      <td>317.51</td>\n",
+       "      <td>314.71</td>\n",
+       "      <td>317.86</td>\n",
+       "      <td>315.06</td>\n",
+       "      <td>317.51</td>\n",
+       "      <td>314.71</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>7</th>\n",
+       "      <td>1958</td>\n",
+       "      <td>06</td>\n",
+       "      <td>21351</td>\n",
+       "      <td>1958.4548</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>317.24</td>\n",
+       "      <td>315.14</td>\n",
+       "      <td>317.24</td>\n",
+       "      <td>315.14</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>8</th>\n",
+       "      <td>1958</td>\n",
+       "      <td>07</td>\n",
+       "      <td>21381</td>\n",
+       "      <td>1958.5370</td>\n",
+       "      <td>315.86</td>\n",
+       "      <td>315.19</td>\n",
+       "      <td>315.86</td>\n",
+       "      <td>315.22</td>\n",
+       "      <td>315.86</td>\n",
+       "      <td>315.19</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>9</th>\n",
+       "      <td>1958</td>\n",
+       "      <td>08</td>\n",
+       "      <td>21412</td>\n",
+       "      <td>1958.6219</td>\n",
+       "      <td>314.93</td>\n",
+       "      <td>316.19</td>\n",
+       "      <td>313.99</td>\n",
+       "      <td>315.29</td>\n",
+       "      <td>314.93</td>\n",
+       "      <td>316.19</td>\n",
+       "    </tr>\n",
+       "  </tbody>\n",
+       "</table>\n",
+       "</div>"
+      ],
+      "text/plain": [
+       "     Yr   Mn      Date        Date        CO2  seasonally          fit  \\\n",
+       "0                                                adjusted                \n",
+       "1                Excel                  [ppm]      [ppm]         [ppm]   \n",
+       "2  1958   01     21200   1958.0411     -99.99      -99.99       -99.99   \n",
+       "3  1958   02     21231   1958.1260     -99.99      -99.99       -99.99   \n",
+       "4  1958   03     21259   1958.2027     315.70      314.44       316.19   \n",
+       "5  1958   04     21290   1958.2877     317.45      315.16       317.30   \n",
+       "6  1958   05     21320   1958.3699     317.51      314.71       317.86   \n",
+       "7  1958   06     21351   1958.4548     -99.99      -99.99       317.24   \n",
+       "8  1958   07     21381   1958.5370     315.86      315.19       315.86   \n",
+       "9  1958   08     21412   1958.6219     314.93      316.19       313.99   \n",
+       "\n",
+       "     seasonally           CO2       seasonally  \n",
+       "0  adjusted fit        filled  adjusted filled  \n",
+       "1         [ppm]         [ppm]            [ppm]  \n",
+       "2        -99.99        -99.99           -99.99  \n",
+       "3        -99.99        -99.99           -99.99  \n",
+       "4        314.91        315.70           314.44  \n",
+       "5        314.99        317.45           315.16  \n",
+       "6        315.06        317.51           314.71  \n",
+       "7        315.14        317.24           315.14  \n",
+       "8        315.22        315.86           315.19  \n",
+       "9        315.29        314.93           316.19  "
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# Vérification des 10 premières lignes, avec des valeurs absentes\n",
+    "# Comparer avec le fichier original !\n",
+    "data.head(10)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/html": [
+       "<div>\n",
+       "<style scoped>\n",
+       "    .dataframe tbody tr th:only-of-type {\n",
+       "        vertical-align: middle;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe tbody tr th {\n",
+       "        vertical-align: top;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe thead th {\n",
+       "        text-align: right;\n",
+       "    }\n",
+       "</style>\n",
+       "<table border=\"1\" class=\"dataframe\">\n",
+       "  <thead>\n",
+       "    <tr style=\"text-align: right;\">\n",
+       "      <th></th>\n",
+       "      <th>Yr</th>\n",
+       "      <th>Mn</th>\n",
+       "      <th>Date</th>\n",
+       "      <th>Date</th>\n",
+       "      <th>CO2</th>\n",
+       "      <th>seasonally</th>\n",
+       "      <th>fit</th>\n",
+       "      <th>seasonally</th>\n",
+       "      <th>CO2</th>\n",
+       "      <th>seasonally</th>\n",
+       "    </tr>\n",
+       "  </thead>\n",
+       "  <tbody>\n",
+       "    <tr>\n",
+       "      <th>748</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>03</td>\n",
+       "      <td>43905</td>\n",
+       "      <td>2020.2049</td>\n",
+       "      <td>414.51</td>\n",
+       "      <td>412.94</td>\n",
+       "      <td>414.84</td>\n",
+       "      <td>413.24</td>\n",
+       "      <td>414.51</td>\n",
+       "      <td>412.94</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>749</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>04</td>\n",
+       "      <td>43936</td>\n",
+       "      <td>2020.2896</td>\n",
+       "      <td>416.18</td>\n",
+       "      <td>413.35</td>\n",
+       "      <td>416.28</td>\n",
+       "      <td>413.43</td>\n",
+       "      <td>416.18</td>\n",
+       "      <td>413.35</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>750</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>05</td>\n",
+       "      <td>43966</td>\n",
+       "      <td>2020.3716</td>\n",
+       "      <td>417.17</td>\n",
+       "      <td>413.75</td>\n",
+       "      <td>417.01</td>\n",
+       "      <td>413.60</td>\n",
+       "      <td>417.17</td>\n",
+       "      <td>413.75</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>751</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>06</td>\n",
+       "      <td>43997</td>\n",
+       "      <td>2020.4563</td>\n",
+       "      <td>416.30</td>\n",
+       "      <td>413.75</td>\n",
+       "      <td>416.31</td>\n",
+       "      <td>413.77</td>\n",
+       "      <td>416.30</td>\n",
+       "      <td>413.75</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>752</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>07</td>\n",
+       "      <td>44027</td>\n",
+       "      <td>2020.5383</td>\n",
+       "      <td>414.49</td>\n",
+       "      <td>413.70</td>\n",
+       "      <td>414.69</td>\n",
+       "      <td>413.94</td>\n",
+       "      <td>414.49</td>\n",
+       "      <td>413.70</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>753</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>08</td>\n",
+       "      <td>44058</td>\n",
+       "      <td>2020.6230</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>754</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>09</td>\n",
+       "      <td>44089</td>\n",
+       "      <td>2020.7077</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>755</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>10</td>\n",
+       "      <td>44119</td>\n",
+       "      <td>2020.7896</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>756</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>11</td>\n",
+       "      <td>44150</td>\n",
+       "      <td>2020.8743</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>757</th>\n",
+       "      <td>2020</td>\n",
+       "      <td>12</td>\n",
+       "      <td>44180</td>\n",
+       "      <td>2020.9563</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "      <td>-99.99</td>\n",
+       "    </tr>\n",
+       "  </tbody>\n",
+       "</table>\n",
+       "</div>"
+      ],
+      "text/plain": [
+       "       Yr   Mn      Date        Date        CO2 seasonally          fit  \\\n",
+       "748  2020   03     43905   2020.2049     414.51     412.94       414.84   \n",
+       "749  2020   04     43936   2020.2896     416.18     413.35       416.28   \n",
+       "750  2020   05     43966   2020.3716     417.17     413.75       417.01   \n",
+       "751  2020   06     43997   2020.4563     416.30     413.75       416.31   \n",
+       "752  2020   07     44027   2020.5383     414.49     413.70       414.69   \n",
+       "753  2020   08     44058   2020.6230     -99.99     -99.99       -99.99   \n",
+       "754  2020   09     44089   2020.7077     -99.99     -99.99       -99.99   \n",
+       "755  2020   10     44119   2020.7896     -99.99     -99.99       -99.99   \n",
+       "756  2020   11     44150   2020.8743     -99.99     -99.99       -99.99   \n",
+       "757  2020   12     44180   2020.9563     -99.99     -99.99       -99.99   \n",
+       "\n",
+       "      seasonally          CO2  seasonally  \n",
+       "748       413.24       414.51      412.94  \n",
+       "749       413.43       416.18      413.35  \n",
+       "750       413.60       417.17      413.75  \n",
+       "751       413.77       416.30      413.75  \n",
+       "752       413.94       414.49      413.70  \n",
+       "753       -99.99       -99.99      -99.99  \n",
+       "754       -99.99       -99.99      -99.99  \n",
+       "755       -99.99       -99.99      -99.99  \n",
+       "756       -99.99       -99.99      -99.99  \n",
+       "757       -99.99       -99.99      -99.99  "
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# Vérification des 10 dernières lignes, avec des valeurs absentes\n",
+    "# Comparer avec le fichier original !\n",
+    "data.tail(10)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# TODO\n",
+    "# Récupérer les entêtes de colonnes\n",
+    "# Vérifier les valeurs à '-99.99'\n",
+    "# Compter les lignes"
+   ]
   }
  ],
  "metadata": {