Question

I am using this code to generate random text :

from collections import defaultdict, Counter
from itertools import ifilter
from random import choice, randrange

def pairwise(iterable):
    it = iter(iterable)
    last = next(it)
    for curr in it:
        yield last, curr
        last = curr

valid = set('abcdefghijklmnopqrstuvwxyz ')
def valid_pair((last, curr)):
    return last in valid and curr in valid

def make_markov(text):
    markov = defaultdict(Counter)
    lowercased = (c.lower() for c in text)
    for p, q in ifilter(valid_pair, pairwise(lowercased)):
        markov[p][q] += 1
    return markov

def genrandom(model, n):
    curr = choice(list(model))
    for i in xrange(n):
        yield curr
        if curr not in model:   # handle case where there is no known successor
            curr = choice(list(model)) #i.e. letter appears for first time at end of text
        d = model[curr]
        target = randrange(sum(d.values()))
        cumulative = 0
        for curr, cnt in d.items():
            cumulative += cnt
            if cumulative > target:
                break

model = make_markov(**'the fox jumped over the fence'**)
print ''.join(genrandom(model, 280))

However, I would like to use a txt file as input instead of ‘the fox jumped over the fence’
I have been trying with :

text=open('moby.txt','r+').read()

and then:

model = make_markov(text)

But it seems that I have something wrong, I’m not sure how to handle this.

Answer 1

Your parameter text is supposed to be the entire contents of Moby Dick , passed in as a string? Try passing the location of the text file and use it as a handle to generate your string from read()

Def makemarcov(fileloc):
    with open(fileloc, 'r') as f:
        text = f.read()
    #proceed...

Im on my phone, otherwise id also include the open() statement within a try clause.

EDIT

The with keyword (if Im not mistaken), uses the yield statement behind the scenes, opening the file using a generator. It uses less resources to read large files.