ref: 2c9e3861a54e22498fb2e3226defe4393b20b202
dir: /sys/src/cmd/python/Demo/scripts/markov.py/
#! /usr/bin/env python
class Markov:
def __init__(self, histsize, choice):
self.histsize = histsize
self.choice = choice
self.trans = {}
def add(self, state, next):
if not self.trans.has_key(state):
self.trans[state] = [next]
else:
self.trans[state].append(next)
def put(self, seq):
n = self.histsize
add = self.add
add(None, seq[:0])
for i in range(len(seq)):
add(seq[max(0, i-n):i], seq[i:i+1])
add(seq[len(seq)-n:], None)
def get(self):
choice = self.choice
trans = self.trans
n = self.histsize
seq = choice(trans[None])
while 1:
subseq = seq[max(0, len(seq)-n):]
options = trans[subseq]
next = choice(options)
if not next: break
seq = seq + next
return seq
def test():
import sys, string, random, getopt
args = sys.argv[1:]
try:
opts, args = getopt.getopt(args, '0123456789cdw')
except getopt.error:
print 'Usage: markov [-#] [-cddqw] [file] ...'
print 'Options:'
print '-#: 1-digit history size (default 2)'
print '-c: characters (default)'
print '-w: words'
print '-d: more debugging output'
print '-q: no debugging output'
print 'Input files (default stdin) are split in paragraphs'
print 'separated blank lines and each paragraph is split'
print 'in words by whitespace, then reconcatenated with'
print 'exactly one space separating words.'
print 'Output consists of paragraphs separated by blank'
print 'lines, where lines are no longer than 72 characters.'
histsize = 2
do_words = 0
debug = 1
for o, a in opts:
if '-0' <= o <= '-9': histsize = eval(o[1:])
if o == '-c': do_words = 0
if o == '-d': debug = debug + 1
if o == '-q': debug = 0
if o == '-w': do_words = 1
if not args: args = ['-']
m = Markov(histsize, random.choice)
try:
for filename in args:
if filename == '-':
f = sys.stdin
if f.isatty():
print 'Sorry, need stdin from file'
continue
else:
f = open(filename, 'r')
if debug: print 'processing', filename, '...'
text = f.read()
f.close()
paralist = string.splitfields(text, '\n\n')
for para in paralist:
if debug > 1: print 'feeding ...'
words = string.split(para)
if words:
if do_words: data = tuple(words)
else: data = string.joinfields(words, ' ')
m.put(data)
except KeyboardInterrupt:
print 'Interrupted -- continue with data read so far'
if not m.trans:
print 'No valid input files'
return
if debug: print 'done.'
if debug > 1:
for key in m.trans.keys():
if key is None or len(key) < histsize:
print repr(key), m.trans[key]
if histsize == 0: print repr(''), m.trans['']
print
while 1:
data = m.get()
if do_words: words = data
else: words = string.split(data)
n = 0
limit = 72
for w in words:
if n + len(w) > limit:
print
n = 0
print w,
n = n + len(w) + 1
print
print
def tuple(list):
if len(list) == 0: return ()
if len(list) == 1: return (list[0],)
i = len(list)/2
return tuple(list[:i]) + tuple(list[i:])
if __name__ == "__main__":
test()