Text Basics.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Text basics in Python"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "75"
      ]
     },
     "execution_count": 1,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text1 = \"Ethics are built right into the ideals and objectives of the United Nations \"\n",
    "len(text1) # Finds length of text"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['Ethics',\n",
       " 'are',\n",
       " 'built',\n",
       " 'right',\n",
       " 'into',\n",
       " 'the',\n",
       " 'ideals',\n",
       " 'and',\n",
       " 'objectives',\n",
       " 'of',\n",
       " 'the',\n",
       " 'United',\n",
       " 'Nations']"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text2 = text1.split(' ') #splitting into different words\n",
    "text2"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Finding Specific Words"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['Ethics',\n",
       " 'built',\n",
       " 'right',\n",
       " 'into',\n",
       " 'ideals',\n",
       " 'objectives',\n",
       " 'United',\n",
       " 'Nations']"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Words more than 3 letters long\n",
    "[w for w in text2 if len(w) > 3]\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['Ethics', 'United', 'Nations']"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "#Capitalized Words\n",
    "[w for w in text2 if w.istitle()]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['Ethics', 'ideals', 'objectives', 'Nations']"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "#words that end with s\n",
    "[w for w in text2 if w.endswith('s')]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Finding unique words: using set()\n",
    "\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['To', 'be', 'or', 'not', 'to', 'be']"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text3 = 'To be or not to be'\n",
    "text4 = text3.split(' ') #splits word\n",
    "text4"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'To', 'be', 'not', 'or', 'to'}"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "set(text4)\n",
    "#note capitalized To and uncapitalized 2 are still there"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "4"
      ]
     },
     "execution_count": 13,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "len(set([w.lower() for w in text4])) #fixes that"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Other functions that can be used\n",
    "\n",
    "s.startswith(t) \n",
    "\n",
    "s.endswith(t)\n",
    "\n",
    "t in s -> finds substring\n",
    "\n",
    "s.isupper(); s.islower(); s.istitle -> first one capitalized, rest are small\n",
    "\n",
    "s.isalpha() -> all alphanumeric\n",
    "\n",
    "s.isdigit() -> just made of digits\n",
    "\n",
    "s.isalnum() -> made of alphabets or numbers\n",
    "\n",
    "s.lower() -> makes it lowercase\n",
    "\n",
    "s.upper() -> uppercase\n",
    "\n",
    "s.titlecase -> first later capitalized, makes it smaller\n",
    "\n",
    "s.split(t) -> splits sentencec based on smaller string t\n",
    "\n",
    "s.splitlines() -> splits sentence on newline/endofline charachter\n",
    "\n",
    "s.join(t) -> joins words in array or list\n",
    "\n",
    "s.strip() -> takes out all whitespace characters from front of string\n",
    "\n",
    "s.rstrip() -> takes out all whitespace characters from end of string\n",
    "\n",
    "s.find(t) -> finds particular substring t in s from front\n",
    "\n",
    "s.rfind(t) -> same as above but from back\n",
    "\n",
    "s.replace(u,v) every instance of u replaced by v"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['', 'agad', 'g', '']"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text5 = 'ouagadougou'\n",
    "text6 = text5.split('ou')\n",
    "text6"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'ouagadougou'"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "'ou'.join(text6)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['o', 'u', 'a', 'g', 'a', 'd', 'o', 'u', 'g', 'o', 'u']"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list(text5)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['o', 'u', 'a', 'g', 'a', 'd', 'o', 'u', 'g', 'o', 'u']"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "[c for c in text5]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Cleaning Text"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['',\n",
       " '',\n",
       " '',\n",
       " '',\n",
       " '',\n",
       " 'A',\n",
       " 'quick',\n",
       " 'brown',\n",
       " 'fox',\n",
       " 'jumped',\n",
       " 'over',\n",
       " 'the',\n",
       " 'lazy',\n",
       " 'dog.',\n",
       " '',\n",
       " '',\n",
       " '']"
      ]
     },
     "execution_count": 18,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text8 = '     A quick brown fox jumped over the lazy dog.   '\n",
    "text8.split(' ')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'A quick brown fox jumped over the lazy dog.'"
      ]
     },
     "execution_count": 23,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text9 = text8.rstrip()\n",
    "text9 = text8.strip()\n",
    "text9"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "10"
      ]
     },
     "execution_count": 24,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text9.find('o')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "40"
      ]
     },
     "execution_count": 25,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text9.rfind('o')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'A quick brOwn fOx jumped Over the lazy dOg.'"
      ]
     },
     "execution_count": 27,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text9.replace('o', 'O')\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Handling Larger Texts"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Universal Declaration of Human Rights - English\\n'"
      ]
     },
     "execution_count": 28,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "f = open('UNDHR.txt', 'r') #'r' symbolizes read mode\n",
    "f.readline()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Reading full file"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "12534"
      ]
     },
     "execution_count": 29,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "f.seek(0)\n",
    "text12 = f.read()\n",
    "len(text12)\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "218"
      ]
     },
     "execution_count": 30,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text13 = text12.splitlines()\n",
    "len(text13)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Universal Declaration of Human Rights - English'"
      ]
     },
     "execution_count": 31,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "text13[0]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### File operations\n",
    "\n",
    "f = open(filename, mode)\n",
    "\n",
    "f.readline(); f.read(); f.read(n) -> n characters\n",
    "\n",
    "for line in f: doSomething(line)\n",
    "\n",
    "f.seek(n) -> resets reading position to n position\n",
    "\n",
    "f.write(message)\n",
    "\n",
    "f.close \n",
    "\n",
    "f.closed -> see if the file has closed"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Issues with reading text files\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Universal Declaration of Human Rights - English\\n'"
      ]
     },
     "execution_count": 33,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "f = open('UNDHR.txt', 'r')\n",
    "text14 = f.readline() \n",
    "text14\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 34,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Universal Declaration of Human Rights - English'"
      ]
     },
     "execution_count": 34,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "#We don't want the backslash n\n",
    "text14.rstrip()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": []
  }
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