{
  "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/calisto1/0350_bucle_for.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "887eb6d8",
      "metadata": {
        "id": "887eb6d8"
      },
      "source": [
        "# Bucle ```for```  \n",
        "\n",
        "Un bucle es una estructura de control que repite un bloque de código un **número conocido de veces**.  \n",
        "\n",
        "El bloque de instrucciones que se repite se denomina **cuerpo del bucle**,  \n",
        "\n",
        "cada repetición se denomina **iteración**."
      ]
    },
    {
      "cell_type": "markdown",
      "id": "5d0df1a8",
      "metadata": {
        "id": "5d0df1a8"
      },
      "source": [
        "## Iterando los elementos de una lista"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 1,
      "id": "ac051410",
      "metadata": {
        "id": "ac051410",
        "outputId": "0c209613-6a03-4638-8a40-ddd14edd37ed",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "naranja\n",
            "banana\n",
            "manzana\n"
          ]
        }
      ],
      "source": [
        "frutas = [\"naranja\", \"banana\", \"manzana\"]\n",
        "for x in frutas:\n",
        "  print(x)"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "286f882a",
      "metadata": {
        "id": "286f882a"
      },
      "source": [
        "La variable de control ```x``` es una variable auxiliar que toma el valor sucesivo de los elementos de la lista."
      ]
    },
    {
      "cell_type": "markdown",
      "id": "effecdca",
      "metadata": {
        "id": "effecdca"
      },
      "source": [
        "## Iterando las letras de una palabra"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 2,
      "id": "ff955d7d",
      "metadata": {
        "id": "ff955d7d",
        "outputId": "c75b11ff-59e1-4229-b1da-ac630ade8d8e",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "b\n",
            "a\n",
            "n\n",
            "a\n",
            "n\n",
            "a\n"
          ]
        }
      ],
      "source": [
        "palabra = \"banana\"\n",
        "for letra in palabra:\n",
        "  print(letra)"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "1fece682",
      "metadata": {
        "id": "1fece682"
      },
      "source": [
        "Ahora la variable de control es ```letra``` que irá tomando sucesivamente los diferentes caracteres del string."
      ]
    },
    {
      "cell_type": "markdown",
      "id": "9cc1ab5f",
      "metadata": {
        "id": "9cc1ab5f"
      },
      "source": [
        "## Usando la función ```range()```"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "6bd9dd64",
      "metadata": {
        "id": "6bd9dd64"
      },
      "source": [
        "Para efectuar un cierto número de ciclos, podemos usar la función ```range()```.  \n",
        "La función ```range()``` devuelve una secuencia de números, comenzando en 0 de forma predeterminada, se incrementa en 1 (de forma predeterminada) y termina en un número especificado."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 3,
      "id": "29b3bbdd",
      "metadata": {
        "id": "29b3bbdd",
        "outputId": "94acc766-9cc0-4ae7-e318-36d7a1ef4626",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "0\n",
            "1\n",
            "2\n",
            "3\n",
            "4\n"
          ]
        }
      ],
      "source": [
        "for i in range(5):           #La variable i toma los valores de 0 a 4\n",
        "    print(i)"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 4,
      "id": "2c023024",
      "metadata": {
        "id": "2c023024",
        "outputId": "751a8ebe-6832-4f73-e49f-9bf94ffc39d4",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "1\n",
            "2\n",
            "3\n",
            "4\n"
          ]
        }
      ],
      "source": [
        "for i in range(1,5):         #La variable i toma los valores de 1 a 4\n",
        "    print(i)"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 5,
      "id": "a6a92e3e",
      "metadata": {
        "id": "a6a92e3e",
        "outputId": "15d278ad-a811-4dc1-f847-3af4ff162cea",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "10\n",
            "12\n",
            "14\n",
            "16\n",
            "18\n"
          ]
        }
      ],
      "source": [
        "for i in range(10,20,2):     #La variable i toma los valores: 10, 12, 14, 16, 18.\n",
        "    print(i)"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 6,
      "id": "a590ab07",
      "metadata": {
        "id": "a590ab07",
        "outputId": "d091dc77-1206-46f2-9dfa-ddf121528244",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "50\n",
            "40\n",
            "30\n",
            "20\n",
            "10\n"
          ]
        }
      ],
      "source": [
        "for i in range(50,0,-10):    #La variable i toma los valores: 50, 40, 30, 20, 10.\n",
        "    print(i)"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "b74cfa38",
      "metadata": {
        "id": "b74cfa38"
      },
      "source": [
        "```range()``` es un objeto de tipo range."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 7,
      "id": "4ede5f19",
      "metadata": {
        "id": "4ede5f19",
        "outputId": "d3a87606-5b20-4efa-aab1-1e7a699501f3",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "range(0, 5)"
            ]
          },
          "metadata": {},
          "execution_count": 7
        }
      ],
      "source": [
        "range(5)"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 8,
      "id": "17cfc14a",
      "metadata": {
        "id": "17cfc14a",
        "outputId": "c6a79f62-4616-4095-ccd3-b9f5c1f59ed0",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "range"
            ]
          },
          "metadata": {},
          "execution_count": 8
        }
      ],
      "source": [
        "type(range(5))"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "3cc63e34",
      "metadata": {
        "id": "3cc63e34"
      },
      "source": [
        "Podemos convertir el objeto range en una lista.  \n",
        "Ocupa menos memoria range(1000) que la lista correspondiente."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 9,
      "id": "6e2bf779",
      "metadata": {
        "id": "6e2bf779",
        "outputId": "36514b78-c91f-4690-9d75-60bdadad931c",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "[0, 1, 2, 3, 4]"
            ]
          },
          "metadata": {},
          "execution_count": 9
        }
      ],
      "source": [
        "list(range(5))"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "b6702712",
      "metadata": {
        "id": "b6702712"
      },
      "source": [
        "## La instrucción ```pass```"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "e285d1a4",
      "metadata": {
        "id": "e285d1a4"
      },
      "source": [
        "Los bucles ```for``` no pueden estar vacíos, pero si está haciendo prueba y aún tiene el bucle ```for``` sin contenido, ingrese la instrucción ```pass``` para evitar errores."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 10,
      "id": "037aa485",
      "metadata": {
        "id": "037aa485"
      },
      "outputs": [],
      "source": [
        "for i in range(10):\n",
        "    pass"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "f2c687a1",
      "metadata": {
        "id": "f2c687a1"
      },
      "source": [
        "## La instrucción ```break```"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "7475bda0",
      "metadata": {
        "id": "7475bda0"
      },
      "source": [
        "Interrumpir con **```break```**. Con la instrucción ```break``` podemos detener el ciclo antes de que haya pasado por todos los elementos"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 11,
      "id": "910085c9",
      "metadata": {
        "id": "910085c9",
        "outputId": "1ce327b2-d562-4533-a594-e63aaaafba5a",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "5\n",
            "7\n",
            "9\n",
            "11\n",
            "13\n",
            "15\n"
          ]
        }
      ],
      "source": [
        "for i in range(5,25,2):\n",
        "    if i == 17:\n",
        "        break\n",
        "\n",
        "    print(i)"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "e14f02a0",
      "metadata": {
        "id": "e14f02a0"
      },
      "source": [
        "En el ejemplo anterior, si convertimos el ```break``` en un comentario, el código nos daría error. Se soluciona poniendo ```pass``` después del comentario."
      ]
    },
    {
      "cell_type": "markdown",
      "id": "3e24b2ce",
      "metadata": {
        "id": "3e24b2ce"
      },
      "source": [
        "**Ejercicio**  \n",
        "¿Qué pasaría si en el ejemplo anterior el ```print``` va antes del ```if```?"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "4689208b",
      "metadata": {
        "id": "4689208b"
      },
      "source": [
        "## La instrucción ```continue```"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "3596d38a",
      "metadata": {
        "id": "3596d38a"
      },
      "source": [
        "Con la instrucción **```continue```** podemos detener la iteración actual del ciclo y continuar con la siguiente."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 12,
      "id": "85db8dc1",
      "metadata": {
        "id": "85db8dc1",
        "outputId": "b87c4a96-5ed2-4614-ba5d-61c69f68893c",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "primavera\n",
            "otoño\n",
            "invierno\n"
          ]
        }
      ],
      "source": [
        "for i in ['primavera', 'verano', 'otoño', 'invierno']:\n",
        "    if i == 'verano':\n",
        "        continue\n",
        "    print(i)"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "78eb271d",
      "metadata": {
        "id": "78eb271d"
      },
      "source": [
        "## La instrucción ```else``` en un bucle ```for```"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "b88978f5",
      "metadata": {
        "id": "b88978f5"
      },
      "source": [
        "```Else``` se ejecutará cuando el bucle haya finalizado."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 13,
      "id": "5d0d49e1",
      "metadata": {
        "id": "5d0d49e1",
        "outputId": "078556c7-bbea-4c22-b440-ac5d893fd3c9",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "0\n",
            "1\n",
            "2\n",
            "3\n",
            "4\n",
            "5\n",
            "El bucle ha finalizado.\n"
          ]
        }
      ],
      "source": [
        "for i in range(6):\n",
        "    print(i)\n",
        "else:\n",
        "    print(\"El bucle ha finalizado.\")"
      ]
    },
    {
      "cell_type": "markdown",
      "id": "7ba92c6d",
      "metadata": {
        "id": "7ba92c6d"
      },
      "source": [
        "La utilidad de ```else``` reside en que si se utiliza en un bucle ```for``` con un ```break```, si se interrumpe la ejecución del bucle, y en ese caso, no se llegará a ejecutar el bloque de código del ```else```."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": 14,
      "id": "582b3521",
      "metadata": {
        "id": "582b3521",
        "outputId": "b424c7d7-5094-463a-d2cf-738652c95276",
        "colab": {
          "base_uri": "https://localhost:8080/"
        }
      },
      "outputs": [
        {
          "output_type": "stream",
          "name": "stdout",
          "text": [
            "0\n",
            "1\n",
            "2\n",
            "3\n"
          ]
        }
      ],
      "source": [
        "for i in range(6):\n",
        "    print(i)\n",
        "    if i == 3:\n",
        "        break\n",
        "else:\n",
        "    print(\"El bucle ha finalizado.\")"
      ]
    }
  ],
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    "kernelspec": {
      "display_name": "Python 3 (ipykernel)",
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    "colab": {
      "name": "0350_bucle_for.ipynb",
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