updated ngrams script so it can also use the nltk model

scripts/ngrams.py

@@ -1,11 +1,12 @@
 #!/usr/bin/env python
 import sys
 import os
+import pickle
 
 libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)), '../lib')
 sys.path.append(libdir)
 import jdecode
-
+import nltk_model as model
 
 def update_ngrams(lines, gramdict, grams):
     for line in lines:
@@ -35,17 +36,48 @@ def describe_bins(gramdict, bins):
             print ('  ' + (str(bins[i]) if i < len(bins) else str(bins[-1]) + '+') 
                    + ': ' + str(counts[i]))
 
-def main(fname, oname, gmin = 2, gmax = 8, verbose = True):
+def extract_language(cards, separate_lines = True):
+    if separate_lines:
+        lang = [line.vectorize() for card in cards for line in card.text_lines]
+    else:
+        lang = [card.text.vectorize() for card in cards]
+    return map(lambda s: s.split(), lang)
+
+def build_ngram_model(cards, n, separate_lines = True, verbose = False):
+    if verbose:
+        print('generating ' + str(n) + '-gram model')
+    lang = extract_language(cards, separate_lines=separate_lines)
+    if verbose:
+        print('found ' + str(len(lang)) + ' sentences')
+    lm = model.NgramModel(n, lang)
+    if verbose:
+        print(lm)
+    return lm
+
+def main(fname, oname, gmin = 2, gmax = 8, nltk = False, sep = False, verbose = False):
+    # may need to set special arguments here
+    cards = jdecode.mtg_open_file(fname, verbose=verbose)
     gmin = int(gmin)
     gmax = int(gmax)
+
+    if nltk:
+        n = gmin
+        lm = build_ngram_model(cards, n, separate_lines=sep, verbose=verbose)
+        if verbose:
+            teststr = 'when @ enters the battlefield'
+            print('litmus test: perplexity of ' + repr(teststr))
+            print('  ' + str(lm.perplexity(teststr.split())))
+        if verbose:
+            print('pickling module to ' + oname)
+        with open(oname, 'wb') as f:
+            pickle.dump(lm, f)
+
+    else:
         bins = [1, 2, 3, 10, 30, 100, 300, 1000]
         if gmin < 2 or gmax < gmin:
             print 'invalid gram sizes: ' + str(gmin) + '-' + str(gmax)
             exit(1)
 
-    # may need to set special arguments here
-    cards = jdecode.mtg_open_file(fname, verbose=verbose)
-
         for grams in range(gmin, gmax+1):
             if verbose:
                 print 'generating ' + str(grams) + '-grams...'
@@ -55,7 +87,8 @@ def main(fname, oname, gmin = 2, gmax = 8, verbose = True):
 
             oname_full = oname + '.' + str(grams) + 'g'
             if verbose:
-            print '  writing ' + str(len(gramdict)) + ' unique ' + str(grams) + '-grams to ' + oname_full
+                print('  writing ' + str(len(gramdict)) + ' unique ' + str(grams) 
+                      + '-grams to ' + oname_full)
                 describe_bins(gramdict, bins)
 
             with open(oname_full, 'wt') as f:
@@ -77,9 +110,14 @@ if __name__ == '__main__':
                         help='minimum gram size to compute')
     parser.add_argument('-max', '--max', action='store', default='8',
                         help='maximum gram size to compute')
+    parser.add_argument('-nltk', '--nltk', action='store_true',
+                        help='use nltk model.NgramModel, with n = min')
+    parser.add_argument('-s', '--separate', action='store_true',
+                        help='separate card text into lines when constructing nltk model')
     parser.add_argument('-v', '--verbose', action='store_true', 
                         help='verbose output')
 
     args = parser.parse_args()
-    main(args.infile, args.outfile, gmin=args.min, gmax=args.max, verbose=args.verbose)
+    main(args.infile, args.outfile, gmin=args.min, gmax=args.max, nltk=args.nltk,
+         sep=args.separate, verbose=args.verbose)
     exit(0)