{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Python - expresiones"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "En Python, una [expresión](https://docs.python.org/3/reference/expressions.html) es una combinación de:\n",
    "* [Literales](https://docs.python.org/3/reference/lexical_analysis.html#literals): valores constantes de números, hileras, listas, booleanos y otros tipos de datos.\n",
    "* Variables.\n",
    "* Los dos anteriores combinados mediante [operadores](https://docs.python.org/3/reference/lexical_analysis.html#operators) o funciones.\n",
    "\n",
    "**Una expresión tiene un valor numérico, textual, booleano o de otro tipo**. En las secciones siguientes se brindan algunos ejemplos de expresiones.\n",
    "\n",
    "**NOTA:** al escribir una expresión en la línea de comandos del interpretador de Python o en un _notebook_, esta retorna su valor. Sin embargo, esto no sucede en un programa. En este último caso, si se quiere visualizar el valor de una expresión, debe imprimirse con la función **print()**, por ejemplo."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Para los ejemplos siguientes, se definen las variables:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [],
   "source": [
    "x = 20\n",
    "y = 21.5\n",
    "h = \"Python\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Expresiones aritméticas"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Se utilizan para realizar operaciones matemáticas con números enteros, complejos o de punto flotante."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Operadores aritméticos\n",
    "\n",
    "<table>\n",
    "\n",
    "<tr><th>Operador</th><th>Descripción</th><th>Ejemplo</th></tr>\n",
    "\n",
    "<tr><td>+</td><td>Suma</td><td>4 + 3 (= 7)</td></tr>\n",
    "<tr><td>-</td><td>Resta</td><td>10 - 5 (= 5)</td></tr>\n",
    "<tr><td>*</td><td>Multiplicación</td><td>3 * 4 (= 12)</td></tr>\n",
    "<tr><td>/</td><td>División</td><td>5 / 2 (= 2.5)</td></tr>\n",
    "<tr><td>//</td><td>División entera</td><td>5 // 2 (= 2)</td></tr>\n",
    "<tr><td>%</td><td>Módulo</td><td>5 % 2 (= 1)</td></tr>\n",
    "<tr><td>**</td><td>Exponenciación</td><td>2 ** 3 (= 8)</td></tr>\n",
    "</table>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Ejemplos"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0"
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Literal\n",
    "0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "20"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Variable\n",
    "x"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "55"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Literal, variable, operador aritmético y función\n",
    "34 + int(y)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Expresiones booleanas"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Se les llama también expresiones lógicas. Tienen solamente dos posibles valores:\n",
    "* **True** (verdadero)\n",
    "* **False** (falso)\n",
    "\n",
    "Son sumamente importantes en Python (y en otros lenguajes de programación) porque con base en expresiones boolenanas se construyen sentencias como condicionales y ciclos."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Operadores booleanos"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "<table>\n",
    "\n",
    "<tr><th>Operador</th><th>Descripción</th><th>Ejemplo</th></tr>\n",
    "\n",
    "<tr><td>and</td><td>Retorna <strong>True</strong> si ambos operandos son verdaderos y <strong>False</strong> en caso contrario</td><td>(1 < 2) and (4 > 3) [= True]</td></tr>\n",
    "<tr><td>or</td><td>Retorna <strong>True</strong> si al menos uno de los operados es verdadero y <strong>False</strong> en caso contrario</td><td>(10 > 20) or (40 < 30) [= False]</td></tr>\n",
    "<tr><td>not</td><td>Retorna <strong>True</strong> si el operando el falso  y <strong>False</strong> en caso contrario</td><td>not (4 > 2) [= False]</td></tr>\n",
    "</table>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Operadores relacionales"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Con frecuencia, las expresiones boolenas incluyen operadores relacionales (de comparación).\n",
    "<table>\n",
    "\n",
    "<tr><th>Operador</th><th>Descripción</th><th>Ejemplo</th></tr>\n",
    "\n",
    "<tr><td>==</td><td>Igual</td><td>(3 + 1) == (2 ** 2)</td></tr>\n",
    "<tr><td>!=</td><td>Diferente</td><td>0 != 1</td></tr>\n",
    "<tr><td>></td><td>Mayor que</td><td>3 > 2</td></tr>\n",
    "<tr><td><</td><td>Menor que</td><td>2 < 3</td></tr>\n",
    "<tr><td>>=</td><td>Mayor o igual que</td><td>3 >= (2 + 1)</td></tr>\n",
    "<tr><td><=</td><td>Menor o igual que</td><td>2 <= 5</td></tr>\n",
    "\n",
    "</table>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Ejemplos"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Literal\n",
    "True"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Literal y variable\n",
    "x == 20"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "False"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Literal, variable y operador\n",
    "x > 100"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Literales, variables, operador aritmético y operador relacional\n",
    "(x + 45) > 10 "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "False"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Literales, variables, operadores aritméticos, operadores relacionales y operadores lógicos\n",
    "((x + 45) > 10) and ((y - 20) <= 0)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Otras expresiones"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Hola Python'"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Hileras\n",
    "\"Hola \" + h"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[1, 2, 3, 'a', 'b', 'c']"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Listas\n",
    "[1, 2, 3] + [\"a\", \"b\", \"c\"]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{10, 20, 40}"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Conjuntos\n",
    "{10, 20, 30, 40, 50} - {30, 50}"
   ]
  }
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