Staging
v0.8.1
v0.8.1
https://github.com/python/cpython
Tip revision: dcd4c4f9c9f9fb75ad4c1f138a285fbe19a9cb61 authored by Ćukasz Langa on 23 March 2020, 16:19:13 UTC
Python 3.9.0a5
Python 3.9.0a5
Tip revision: dcd4c4f
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')
with f:
if debug: print('processing', filename, '...')
text = f.read()
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()