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