six_CFGParse.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "import nltk\n",
    "from nltk import *"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "grammar = nltk.CFG.fromstring(\"\"\"\n",
    "  S -> NP VP\n",
    "  VP -> V NP | V NP PP\n",
    "  PP -> P NP\n",
    "  V -> \"saw\" | \"ate\" | \"walked\"\n",
    "  NP -> Prop | Det N | Det N PP\n",
    "  Prop -> \"John\" | \"Mary\" | \"Bob\" \n",
    "  Det -> \"a\" | \"an\" | \"the\" | \"my\"\n",
    "  N -> \"man\" | \"dog\" | \"cat\" | \"telescope\" | \"park\"\n",
    "  P -> \"in\" | \"on\" | \"by\" | \"with\"\n",
    "  \"\"\")\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "rd_parser = nltk.RecursiveDescentParser(grammar)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "senttext = \"Mary saw Bob\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "sentlist = senttext.split()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "trees = rd_parser.parse(sentlist)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "generator"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "type(trees)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "nltk.tree.Tree"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "treelist = list(trees)\n",
    "type(treelist[0]) "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(S (NP (Prop Mary)) (VP (V saw) (NP (Prop Bob))))\n"
     ]
    }
   ],
   "source": [
    "for tree in treelist:\n",
    "\tprint (tree)\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "nltk.tree.Tree"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "type(treelist[0])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "treelist = list(trees)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "sent2list = \"John saw the man in the park with a telescope\".split()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(S\n",
      "  (NP (Prop John))\n",
      "  (VP\n",
      "    (V saw)\n",
      "    (NP\n",
      "      (Det the)\n",
      "      (N man)\n",
      "      (PP\n",
      "        (P in)\n",
      "        (NP\n",
      "          (Det the)\n",
      "          (N park)\n",
      "          (PP (P with) (NP (Det a) (N telescope))))))))\n",
      "(S\n",
      "  (NP (Prop John))\n",
      "  (VP\n",
      "    (V saw)\n",
      "    (NP (Det the) (N man))\n",
      "    (PP\n",
      "      (P in)\n",
      "      (NP\n",
      "        (Det the)\n",
      "        (N park)\n",
      "        (PP (P with) (NP (Det a) (N telescope)))))))\n",
      "(S\n",
      "  (NP (Prop John))\n",
      "  (VP\n",
      "    (V saw)\n",
      "    (NP (Det the) (N man) (PP (P in) (NP (Det the) (N park))))\n",
      "    (PP (P with) (NP (Det a) (N telescope)))))\n"
     ]
    }
   ],
   "source": [
    "for tree in rd_parser.parse(sent2list):\n",
    "\tprint (tree)\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "sent3list = \"Bob ate the park with my cat on the telescope\".split()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(S\n",
      "  (NP (Prop Bob))\n",
      "  (VP\n",
      "    (V ate)\n",
      "    (NP\n",
      "      (Det the)\n",
      "      (N park)\n",
      "      (PP\n",
      "        (P with)\n",
      "        (NP\n",
      "          (Det my)\n",
      "          (N cat)\n",
      "          (PP (P on) (NP (Det the) (N telescope))))))))\n",
      "(S\n",
      "  (NP (Prop Bob))\n",
      "  (VP\n",
      "    (V ate)\n",
      "    (NP (Det the) (N park))\n",
      "    (PP\n",
      "      (P with)\n",
      "      (NP (Det my) (N cat) (PP (P on) (NP (Det the) (N telescope)))))))\n",
      "(S\n",
      "  (NP (Prop Bob))\n",
      "  (VP\n",
      "    (V ate)\n",
      "    (NP (Det the) (N park) (PP (P with) (NP (Det my) (N cat))))\n",
      "    (PP (P on) (NP (Det the) (N telescope)))))\n"
     ]
    }
   ],
   "source": [
    "for tree in rd_parser.parse(sent3list):\n",
    "\tprint (tree)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "groucho_grammar = nltk.CFG.fromstring(\"\"\"\n",
    "  S -> NP VP\n",
    "  VP -> V NP | V NP PP\n",
    "  PP -> P NP\n",
    "  V -> \"saw\" | \"ate\" | \"walked\" | \"shot\"\n",
    "  NP -> Prop | Det N | Det N PP\n",
    "  Prop -> \"John\" | \"Mary\" | \"Bob\" | \"I\"\n",
    "  Det -> \"a\" | \"an\" | \"the\" | \"my\"\n",
    "  N -> \"man\" | \"dog\" | \"cat\" | \"telescope\" | \"park\" | \"elephant\" | \"pajamas\"\n",
    "  P -> \"in\" | \"on\" | \"by\" | \"with\"\n",
    "  \"\"\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "sent4list = \"I shot an elephant in my pajamas\".split()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(S\n",
      "  (NP (Prop I))\n",
      "  (VP\n",
      "    (V shot)\n",
      "    (NP (Det an) (N elephant) (PP (P in) (NP (Det my) (N pajamas))))))\n",
      "(S\n",
      "  (NP (Prop I))\n",
      "  (VP\n",
      "    (V shot)\n",
      "    (NP (Det an) (N elephant))\n",
      "    (PP (P in) (NP (Det my) (N pajamas)))))\n"
     ]
    }
   ],
   "source": [
    "rd_parser = nltk.RecursiveDescentParser(groucho_grammar)\n",
    "for tree in rd_parser.parse(sent4list):\n",
    "\tprint (tree)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "flight_grammar = nltk.CFG.fromstring(\"\"\"\n",
    "  S -> NP VP | VP\n",
    "  VP -> V NP | V NP PP\n",
    "  PP -> P NP\n",
    "  V -> \"saw\" | \"ate\" | \"walked\" | \"shot\" | \"book\"\n",
    "  NP -> Prop | Det N | Det N PP\n",
    "  Prop -> \"John\" | \"Mary\" | \"Bob\" | \"I\"\n",
    "  Det -> \"a\" | \"an\" | \"the\" | \"my\" | \"that\"\n",
    "  N -> \"man\" | \"dog\" | \"cat\" | \"telescope\" | \"park\" | \"elephant\" | \"pajamas\" | \"flight\"\n",
    "  P -> \"in\" | \"on\" | \"by\" | \"with\"\n",
    "  \"\"\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(S (VP (V book) (NP (Det that) (N flight))))\n"
     ]
    }
   ],
   "source": [
    "rd_parser = nltk.RecursiveDescentParser(flight_grammar)\n",
    "sent5list = 'book that flight'.split()\n",
    "for tree in rd_parser.parse(sent5list):\n",
    "\tprint (tree)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "groucho_dep_grammar = nltk.DependencyGrammar.fromstring(\"\"\"\n",
    "  'shot' -> 'I' | 'elephant' | 'in'\n",
    "  'elephant' -> 'an'\n",
    "  'in' -> 'pajamas'\n",
    "  'pajamas' -> 'my'\n",
    "  \"\"\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Dependency grammar with 6 productions\n",
      "  'shot' -> 'I'\n",
      "  'shot' -> 'elephant'\n",
      "  'shot' -> 'in'\n",
      "  'elephant' -> 'an'\n",
      "  'in' -> 'pajamas'\n",
      "  'pajamas' -> 'my'\n"
     ]
    }
   ],
   "source": [
    "print (groucho_dep_grammar)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(shot I (elephant an) (in (pajamas my)))\n"
     ]
    }
   ],
   "source": [
    "pdp = nltk.ProjectiveDependencyParser(groucho_dep_grammar)\n",
    "glist = 'I shot an elephant in my pajamas'.split()\n",
    "trees = pdp.parse(glist)\n",
    "for tree in trees:\n",
    "    print (tree)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "flight1_grammar = nltk.CFG.fromstring(\"\"\"\n",
    "  S -> NP VP | VP\n",
    "  VP -> V NP | V NP PP\n",
    "  PP -> P NP\n",
    "  V -> \"saw\" | \"ate\" | \"walked\" | \"shot\" | \"book\" |\"want\"\n",
    "  NP -> Prop | Det N | Det N PP\n",
    "  Prop -> \"John\" | \"Mary\" | \"Bob\" | \"I\"\n",
    "  Det -> \"a\" | \"an\" | \"the\" | \"my\" | \"that\"\n",
    "  N -> \"man\" | \"dog\" | \"cat\" | \"telescope\" | \"park\" | \"elephant\" | \"pajamas\" | \"flight\"\n",
    "  P -> \"in\" | \"on\" | \"by\" | \"with\" | \"to\"\n",
    "  \"\"\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "rd_parser = nltk.RecursiveDescentParser(flight1_grammar)\n",
    "sent6list = 'I want to book that flight'.split()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 34,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "for tree in rd_parser.parse(sent6list):\n",
    "\tprint (tree)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(S\n",
      "  (NP (Prop I))\n",
      "  (VP (V want) (PP (P to)) (V book) (NP (Det that) (N flight))))\n"
     ]
    }
   ],
   "source": [
    "import nltk\n",
    "flight_grammar = nltk.CFG.fromstring(\"\"\" \n",
    "    S -> NP VP| VP \n",
    "    VP -> V | V NP | V NP PP | V PP V NP | V PP NP\n",
    "    PP -> P NP | P | PV  \n",
    "    V -> \"saw\" | \"ate\" | \"walked\" | \"shot\" | \"book\" | \"want\" | \"walked\" | \"prefer\"\n",
    "    NP -> Prop | Det N | Det N PP \n",
    "    Prop -> \"John\" | \"Mary\" | \"Bob\" | \"I\" | \"Jack\" | \"Houston\" \n",
    "    Det -> \"a\" | \"an\" | \"the\" | \"my\" | \"that\" \n",
    "    N -> \"man\" | \"dog\" | \"cat\" | \"telescope\" | \"park\" | \"elephant\" | \"pajamas\" | \"flight\" | \"dog\"\n",
    "    P -> \"in\" | \"on\" | \"by\" | \"with\" | \"to\" | \"through\"  \"\"\")\n",
    "rd_parser = nltk.RecursiveDescentParser(flight_grammar)\n",
    "sentlist = 'I want to book that flight'.split()\n",
    "for tree in rd_parser.parse(sentlist): \n",
    "    print(tree)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 41,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(S\n",
      "  (NP (Prop Jack))\n",
      "  (VP (V walked) (PP (P with) (NP (Det the) (N dog)))))\n"
     ]
    }
   ],
   "source": [
    "flight_grammar1 = nltk.CFG.fromstring(\"\"\" \n",
    "\n",
    "S -> NP VP | VP\n",
    "\n",
    "VP -> V NP | V NP PP | V TO VP | V PP \n",
    "\n",
    "PP -> P NP\n",
    "\n",
    "V -> \"saw\" | \"want\" | \"walked\" | \"shot\" | \"book\" | \"prefer\" | \"eat\"\n",
    "\n",
    "NP -> Prop | Det N | Det N PP\n",
    "\n",
    "Prop -> \"Jack\" | \"I\" | \"Houston\"  \n",
    "Det -> \"a\" | \"an\" | \"the\" | \"my\" | \"that\"\n",
    "\n",
    "N -> \"man\" | \"dog\" | \"cat\" | \"telescope\" | \"park\" | \"elephant\" | \"pajamas\" | \"flight\" | \"apple\"\n",
    "\n",
    "P -> \"in\" | \"on\" | \"by\" | \"with\" | \"through\"  \n",
    "TO -> \"to\"\n",
    "\n",
    "\"\"\")\n",
    "rd_parser = nltk.RecursiveDescentParser(flight_grammar1)\n",
    "sentlist = 'Jack walked with the dog'.split()\n",
    "for tree in rd_parser.parse(sentlist): \n",
    "    print(tree)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": []
  }
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