def demo(): """ A demonstration showing how C{Grammar}s can be created and used. """ from nltk import cfg # Create some nonterminals S, NP, VP, PP = cfg.nonterminals('S, NP, VP, PP') N, V, P, Det = cfg.nonterminals('N, V, P, Det') VP_slash_NP = VP/NP print 'Some nonterminals:', [S, NP, VP, PP, N, V, P, Det, VP/NP] print ' S.symbol() =>', `S.symbol()` print print cfg.Production(S, [NP]) # Create some Grammar Productions grammar = cfg.parse_grammar(""" S -> NP VP PP -> P NP NP -> Det N NP -> NP PP VP -> V NP VP -> VP PP Det -> 'a' Det -> 'the' N -> 'dog' N -> 'cat' V -> 'chased' V -> 'sat' P -> 'on' P -> 'in' """) print 'A Grammar:', `grammar` print ' grammar.start() =>', `grammar.start()` print ' grammar.productions() =>', # Use string.replace(...) is to line-wrap the output. print `grammar.productions()`.replace(',', ',\n'+' '*25) print
def demo(): """ A demonstration showing how C{Grammar}s can be created and used. """ from nltk import cfg # Create some nonterminals S, NP, VP, PP = cfg.nonterminals('S, NP, VP, PP') N, V, P, Det = cfg.nonterminals('N, V, P, Det') VP_slash_NP = VP / NP print 'Some nonterminals:', [S, NP, VP, PP, N, V, P, Det, VP / NP] print ' S.symbol() =>', ` S.symbol() ` print print cfg.Production(S, [NP]) # Create some Grammar Productions grammar = cfg.parse_grammar(""" S -> NP VP PP -> P NP NP -> Det N NP -> NP PP VP -> V NP VP -> VP PP Det -> 'a' Det -> 'the' N -> 'dog' N -> 'cat' V -> 'chased' V -> 'sat' P -> 'on' P -> 'in' """) print 'A Grammar:', ` grammar ` print ' grammar.start() =>', ` grammar.start() ` print ' grammar.productions() =>', # Use string.replace(...) is to line-wrap the output. print ` grammar.productions() `.replace(',', ',\n' + ' ' * 25) print
def main(): sentence = 'The quick brown fox jumped over the lazy dog' grammar = cfg.parse_grammar(read('demo.cfg')) # load from pickle so it's faster tagger = pickle.load(open('demo_tagger.pickle')) tagged_chart_parse(sentence, grammar, tagger)