dave wrote:
Hi Guys,
I've written a Markov analysis program and would like to get your
comments on the code As it stands now the final input comes out as a
tuple, then list, then tuple. Something like ('the', 'water') ['us']
('we', 'took')..etc...
I'm still learning so I don't know any advanced techniques or methods
that may have made this easier.
here's the code:
def makelist(f): #turn a document into a list
fin = open(f)
results = []
for line in fin:
line = line.replace('"', '')
line = line.strip().split()
for word in line:
results.append(word)
return results
What's you data look like? Just straight text?
def markov(f, preflen=2): #f is the file to analyze, preflen is
prefix length
convert_file = makelist(f)
mapdict = {} #dict where the prefixes will map to suffixes
start = 0
end = preflen #start/end set the slice size
for words in convert_file:
prefix = tuple(convert_file[start:end]) #tuple as mapdict key
suffix = convert_file[start + 2 : end + 1] #word as suffix to key
mapdict[prefix] = mapdict.get(prefix, []) + suffix #append suffixes
start += 1
end += 1
return mapdict
What is convert_file??
def randsent(f, amt=10): #prints a random sentence
analyze = markov(f)
for i in range(amt):
rkey = random.choice(analyze.keys())
print rkey, analyze[rkey],
The book gave a hint saying to make the prefixes in the dict using:
def shift(prefix, word):
return prefix[1:] + (word, )
That's not a very helpful hint.
It works if you call it with a tuple and a word --- it shifts off the
front of the tuple ... so :
shift(('foo','bar') "word")
becomes ('bar', 'word')
Whoopty doo --- I'm not sure what that accomplishes!!
Unless the author means "pass a list and a randomly pick a word from the
list" in which case the return statement could be
random.choice(prefix) + (word, )
* shrug *
But -- that's not very Markov ... you'd want a weighted choice of words
... depending on how you define your Markov chain -- say a Markov chain
based on part-of-speech or probability of occurrence from a given word-set.
Can you give some more detail??
However I can't seem to wrap my head around incorporating that into the
code above, if you know a method or could point me in the right
direction (or think that I don't need to use it) please let me know.
Thanks for all your help,
Dave
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