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   "source": [
    "[prev: Fonctions d'ordre supérieur](higher-order-function.ipynb) | [home](../index.ipynb) | [next: Rendre un script importable](good-script.ipynb)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Les générateurs\n"
   ]
  },
  {
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   "metadata": {},
   "source": [
    "Les générateurs sont:\n",
    "\n",
    "- des fabriques à itérables\n",
    "\n",
    "\n",
    "- sont créés comme des fonctions mais utilisent `yield` à la place de `return`.\n",
    "\n",
    "\n",
    "Ils s'agit donc d'un moyen simple de réaliser des boucles complexes."
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     "text": [
      "<class 'function'>\n",
      "<function carre_decroissant at 0x7fb1e02c7d90>\n"
     ]
    }
   ],
   "source": [
    "# Principe de mise en oeuvre\n",
    "\n",
    "def carre_decroissant(valeur):  # def comme pour une fonction\n",
    "    valeur = int(valeur)\n",
    "    while valeur:               # une boucle, ici : while\n",
    "        yield valeur ** 2       # yield dans la boucle\n",
    "        valeur -= 1\n",
    "\n",
    "print(type(carre_decroissant))\n",
    "print(carre_decroissant)"
   ]
  },
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   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
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     "text": [
      "<class 'generator'>\n",
      "<generator object carre_decroissant at 0x7fb1e02abdb0>\n"
     ]
    }
   ],
   "source": [
    "# construction d'un générateur\n",
    "\n",
    "generateur = carre_decroissant(5)\n",
    "\n",
    "print(type(generateur))\n",
    "print(generateur)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
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     "text": [
      "25\n",
      "16\n",
      "9\n",
      "4\n",
      "1\n"
     ]
    }
   ],
   "source": [
    "# exploitation du générateur\n",
    "\n",
    "for valeur in generateur:\n",
    "    print(valeur)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Exercices"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- [Suite de Collatz (bonus)](../exercises/exercises.ipynb#Exercice-6-:-suite-de-Collatz)"
   ]
  }
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