début de l'exercice sur le CO2

module3/exo3/exercice_fr.ipynb

 {
- "cells": [],
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Concentration de CO2 dans l'atmosphère depuis 1958\n",
+    "\n",
+    "On s'intéresse à la concentration en CO2 au cours du temps depuis 1958; les données sont disponibles sur le site web [scrippsco2.ucsd.edu](https://scrippsco2.ucsd.edu/data/atmospheric_co2/primary_mlo_co2_record.html)\n",
+    "\n",
+    "Commençons par importer les bibliothèques nécessaires à l'analyse"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "%matplotlib inline\n",
+    "import matplotlib.pyplot as plt\n",
+    "import numpy as np\n",
+    "import pandas as pd\n",
+    "import isoweek"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Chargeons à présent les données"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def skiprows(x):\n",
+    "    return x < 62 or x in [63,64]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Données disponibles en local, téléchargement en cours\n"
+     ]
+    }
+   ],
+   "source": [
+    "data_url = \"https://scrippsco2.ucsd.edu/assets/data/atmospheric/stations/in_situ_co2/monthly/monthly_in_situ_co2_mlo.csv\"\n",
+    "data_path = \"./monthly_in_situ_co2_mlo.csv\"\n",
+    "\n",
+    "try:\n",
+    "    data = pd.read_csv(data_path)\n",
+    "    print(\"Données disponibles en local, téléchargement en cours\")\n",
+    "except FileNotFoundError as e:\n",
+    "    print(\"Données non disponibles, téléchargement...\")\n",
+    "    data = pd.read_csv(data_url,skiprows=skiprows)\n",
+    "    data.to_csv(data_path)\n",
+    "    print(\"Téléchargement et enregistrement terminé\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
  "metadata": {
   "kernelspec": {
    "display_name": "Python 3",
@@ -16,10 +92,9 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.3"
+   "version": "3.6.4"
   }
  },
  "nbformat": 4,
  "nbformat_minor": 2
 }
-