{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "view-in-github",
        "colab_type": "text"
      },
      "source": [
        "<a href=\"https://colab.research.google.com/github/financieras/pyCourse/blob/main/jupyter/calisto1/0540_funciones2.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "wwbIjbttDKfO"
      },
      "source": [
        "# Introducción a las funciones [2]"
      ],
      "id": "wwbIjbttDKfO"
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "uKZ4MT6iDKfQ"
      },
      "source": [
        "## El operador asterisco\n",
        "Cuando tenemos un número indeterminado de argumentos"
      ],
      "id": "uKZ4MT6iDKfQ"
    },
    {
      "cell_type": "code",
      "execution_count": 1,
      "metadata": {
        "id": "QepenHRLDKfR",
        "outputId": "f214f377-db4c-41dc-8b0e-7c73d0693cb6",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "El mayor en la fiesta tenía 30 años\n"
          ]
        }
      ],
      "source": [
        "def mimax(*edades):             #cuando no se sabe el número de argumentos se pone asterisco\n",
        "  print(f\"El mayor en la fiesta tenía {max(edades)} años\")\n",
        "\n",
        "mimax(20, 30, 18, 24, 26)"
      ],
      "id": "QepenHRLDKfR"
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "WGv4Xx5ADKfS"
      },
      "source": [
        "## Valor por defecto de un argumento"
      ],
      "id": "WGv4Xx5ADKfS"
    },
    {
      "cell_type": "code",
      "execution_count": 2,
      "metadata": {
        "id": "FphL_DaqDKfT",
        "outputId": "095786fc-791e-458c-c371-550c35c484c3",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "De postre mejor una fruta, por ejemplo manzana\n",
            "De postre mejor una fruta, por ejemplo naranja\n"
          ]
        }
      ],
      "source": [
        "def postre(fruta = \"naranja\"):\n",
        "    return \"De postre mejor una fruta, por ejemplo \" + fruta\n",
        "\n",
        "print(postre('manzana'))\n",
        "print(postre())                #si no se especifica un argumento se toma el valor por defecto"
      ],
      "id": "FphL_DaqDKfT"
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "DPzCvtbmDKfT"
      },
      "source": [
        "## Función con dos return\n",
        "Cuando una función no lleva return el compilador añade al final un ```return True```.  \n",
        "\n",
        "Si en una función hay dos returns solo se ejecuta el primero ya que finaliza la función."
      ],
      "id": "DPzCvtbmDKfT"
    },
    {
      "cell_type": "code",
      "execution_count": 3,
      "metadata": {
        "id": "IL2DoO7-DKfU",
        "outputId": "f14b28dc-2065-4354-f1d9-dd8530b5ae64",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "Este verano viajaré hacia el Norte\n"
          ]
        }
      ],
      "source": [
        "import random\n",
        "\n",
        "def destino(numero):\n",
        "    if numero == 1:\n",
        "        return 'Norte'\n",
        "    if numero == 2:\n",
        "        return 'Sur'\n",
        "\n",
        "aleatorio = random.randint(1,2)\n",
        "punto_cardinal = destino(aleatorio)\n",
        "print(\"Este verano viajaré hacia el\", punto_cardinal)"
      ],
      "id": "IL2DoO7-DKfU"
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "vqqeuuwUDKfU"
      },
      "source": [
        "## Nº argumentos = Nº parámetros\n",
        "Cuando esto no sucede se produce un error."
      ],
      "id": "vqqeuuwUDKfU"
    },
    {
      "cell_type": "code",
      "execution_count": 4,
      "metadata": {
        "id": "caZ2ylbTDKfV"
      },
      "outputs": [],
      "source": [
        "def suma(a,b):\n",
        "    return a+b\n",
        "\n",
        "#suma(10)                         # error"
      ],
      "id": "caZ2ylbTDKfV"
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "BZTtHveTDKfV"
      },
      "source": [
        "Una posible solución es establecer unos valores por defecto de tipo ```None``` y luego con un ```if``` controlar el error."
      ],
      "id": "BZTtHveTDKfV"
    },
    {
      "cell_type": "code",
      "execution_count": 5,
      "metadata": {
        "id": "bxqDOf01DKfV",
        "outputId": "1e78f954-a721-49e4-d101-e1e7f9e87bd8",
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 35
        }
      },
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "'Error: se han de pasar dos argumentos'"
            ],
            "application/vnd.google.colaboratory.intrinsic+json": {
              "type": "string"
            }
          },
          "metadata": {},
          "execution_count": 5
        }
      ],
      "source": [
        "def suma(a=None,b=None):\n",
        "    if a==None or b==None: return \"Error: se han de pasar dos argumentos\"\n",
        "    else: return a+b              # sin el else también funciona\n",
        "\n",
        "suma()"
      ],
      "id": "bxqDOf01DKfV"
    },
    {
      "cell_type": "code",
      "execution_count": 6,
      "metadata": {
        "id": "ykm6lLNkDKfW",
        "outputId": "f7eaae85-c364-48c1-ae52-9872cfc89740",
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 35
        }
      },
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "'Error: se han de pasar dos argumentos'"
            ],
            "application/vnd.google.colaboratory.intrinsic+json": {
              "type": "string"
            }
          },
          "metadata": {},
          "execution_count": 6
        }
      ],
      "source": [
        "suma(10)"
      ],
      "id": "ykm6lLNkDKfW"
    },
    {
      "cell_type": "code",
      "execution_count": 7,
      "metadata": {
        "id": "1ZsBFt7oDKfW",
        "outputId": "5729799c-a278-412b-9907-30cccef867c3",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "15"
            ]
          },
          "metadata": {},
          "execution_count": 7
        }
      ],
      "source": [
        "suma(10,5)"
      ],
      "id": "1ZsBFt7oDKfW"
    }
  ],
  "metadata": {
    "kernelspec": {
      "display_name": "Python 3",
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      },
      "file_extension": ".py",
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      "name": "python",
      "nbconvert_exporter": "python",
      "pygments_lexer": "ipython3",
      "version": "3.8.5"
    },
    "colab": {
      "name": "0540_funciones2.ipynb",
      "provenance": [],
      "include_colab_link": true
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