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v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: 2142ee8718d9eb2f055c07efcf66284512f7fa61 authored by Georg Brandl on 23 February 2012, 20:19:25 UTC
Update copyright year.
Update copyright year.
Tip revision: 2142ee8
markov.py
#!/usr/bin/env python3
"""
Markov chain simulation of words or characters.
"""
class Markov:
def __init__(self, histsize, choice):
self.histsize = histsize
self.choice = choice
self.trans = {}
def add(self, state, next):
self.trans.setdefault(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 True:
subseq = seq[max(0, len(seq)-n):]
options = trans[subseq]
next = choice(options)
if not next:
break
seq += next
return seq
def test():
import sys, random, getopt
args = sys.argv[1:]
try:
opts, args = getopt.getopt(args, '0123456789cdwq')
except getopt.error:
print('Usage: %s [-#] [-cddqw] [file] ...' % sys.argv[0])
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.')
sys.exit(2)
histsize = 2
do_words = False
debug = 1
for o, a in opts:
if '-0' <= o <= '-9': histsize = int(o[1:])
if o == '-c': do_words = False
if o == '-d': debug += 1
if o == '-q': debug = 0
if o == '-w': do_words = True
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 = text.split('\n\n')
for para in paralist:
if debug > 1: print('feeding ...')
words = para.split()
if words:
if do_words:
data = tuple(words)
else:
data = ' '.join(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 True:
data = m.get()
if do_words:
words = data
else:
words = data.split()
n = 0
limit = 72
for w in words:
if n + len(w) > limit:
print()
n = 0
print(w, end=' ')
n += len(w) + 1
print()
print()
if __name__ == "__main__":
test()