Demo/scripts/markov.py

   1 #! /usr/bin/env python
   2
   3 class Markov:
   4     def __init__(self, histsize, choice):
   5         self.histsize = histsize
   6         self.choice = choice
   7         self.trans = {}
   8
   9     def add(self, state, next):
  10         self.trans.setdefault(state, []).append(next)
  11
  12     def put(self, seq):
  13         n = self.histsize
  14         add = self.add
  15         add(None, seq[:0])
  16         for i in range(len(seq)):
  17             add(seq[max(0, i-n):i], seq[i:i+1])
  18         add(seq[len(seq)-n:], None)
  19
  20     def get(self):
  21         choice = self.choice
  22         trans = self.trans
  23         n = self.histsize
  24         seq = choice(trans[None])
  25         while True:
  26             subseq = seq[max(0, len(seq)-n):]
  27             options = trans[subseq]
  28             next = choice(options)
  29             if not next:
  30                 break
  31             seq += next
  32         return seq
  33
  34
  35 def test():
  36     import sys, random, getopt
  37     args = sys.argv[1:]
  38     try:
  39         opts, args = getopt.getopt(args, '0123456789cdwq')
  40     except getopt.error:
  41         print 'Usage: %s [-#] [-cddqw] [file] ...' % sys.argv[0]
  42         print 'Options:'
  43         print '-#: 1-digit history size (default 2)'
  44         print '-c: characters (default)'
  45         print '-w: words'
  46         print '-d: more debugging output'
  47         print '-q: no debugging output'
  48         print 'Input files (default stdin) are split in paragraphs'
  49         print 'separated blank lines and each paragraph is split'
  50         print 'in words by whitespace, then reconcatenated with'
  51         print 'exactly one space separating words.'
  52         print 'Output consists of paragraphs separated by blank'
  53         print 'lines, where lines are no longer than 72 characters.'
  54         sys.exit(2)
  55     histsize = 2
  56     do_words = False
  57     debug = 1
  58     for o, a in opts:
  59         if '-0' <= o <= '-9': histsize = int(o[1:])
  60         if o == '-c': do_words = False
  61         if o == '-d': debug += 1
  62         if o == '-q': debug = 0
  63         if o == '-w': do_words = True
  64     if not args:
  65         args = ['-']
  66
  67     m = Markov(histsize, random.choice)
  68     try:
  69         for filename in args:
  70             if filename == '-':
  71                 f = sys.stdin
  72                 if f.isatty():
  73                     print 'Sorry, need stdin from file'
  74                     continue
  75             else:
  76                 f = open(filename, 'r')
  77             if debug: print 'processing', filename, '...'
  78             text = f.read()
  79             f.close()
  80             paralist = text.split('\n\n')
  81             for para in paralist:
  82                 if debug > 1: print 'feeding ...'
  83                 words = para.split()
  84                 if words:
  85                     if do_words:
  86                         data = tuple(words)
  87                     else:
  88                         data = ' '.join(words)
  89                     m.put(data)
  90     except KeyboardInterrupt:
  91         print 'Interrupted -- continue with data read so far'
  92     if not m.trans:
  93         print 'No valid input files'
  94         return
  95     if debug: print 'done.'
  96
  97     if debug > 1:
  98         for key in m.trans.keys():
  99             if key is None or len(key) < histsize:
 100                 print repr(key), m.trans[key]
 101         if histsize == 0: print repr(''), m.trans['']
 102         print
 103     while True:
 104         data = m.get()
 105         if do_words:
 106             words = data
 107         else:
 108             words = data.split()
 109         n = 0
 110         limit = 72
 111         for w in words:
 112             if n + len(w) > limit:
 113                 print
 114                 n = 0
 115             print w,
 116             n += len(w) + 1
 117         print
 118         print
 119
 120 if __name__ == "__main__":
 121     test()