marc alternatives and similar packages

About

marc (markov chain) is a small, but flexible Markov chain generator.

Usage

marc is easy to use. To build a MarkovChain pass the object a sequence of items:

from marc import MarkovChain
sequence = [
 'Rock', 'Rock', 'Rock', 'Paper', 'Rock', 'Scissors',
 'Paper', 'Paper', 'Scissors', 'Rock', 'Scissors',
 'Scissors', 'Paper', 'Scissors', 'Rock', 'Rock', 'Rock',
 'Paper', 'Scissors', 'Scissors', 'Scissors', 'Rock'
]
chain = MarkovChain(sequence)

The learned transition matrix can be accessed through the matrix attribute:

print(chain.matrix)
# [[0.5, 0.25, 0.25], [0.2, 0.2, 0.6], [0.375, 0.25, 0.375]]

Though, the output is perhaps better viewed as a pandas DataFrame:

import pandas as pd
df = pd.DataFrame(
 chain.matrix,
 index=chain.encoder.index_,
 columns=chain.encoder.index_
)
print(df)
# Rock Paper Scissors
# Rock 0.500 0.25 0.250
# Paper 0.200 0.20 0.600
# Scissors 0.375 0.25 0.375

Use the next method to generate the next state (seeded or unseeded):

chain.next('Rock')
# 'Rock'
chain.next()
# Paper

The next method can also generate multiple states with the n argument:

chain.next('Paper', n=5)
# ['Scissors', 'Paper', 'Rock', 'Paper', 'Scissors']

MarkovChain objects are iterable. This means that they can be passed directly to the next function:

next(chain)
# 'Scissors'
next(chain)
# Rock

Example

A fully worked example of marc in action (block text provided by quote):

import random
import re
from quote import quote
from marc import MarkovChain
quotes = quote('shakespeare', 250)
print(quotes[0])
# {'author': 'William Shakespeare',
# 'book': 'As You Like It',
# 'quote': 'The fool doth think he is wise, but the wise man knows himself to be a fool.'}
text = '\n'.join([q['quote'] for q in quotes])
text = text.lower()
tokens = re.findall(r"[\w']+|[.,!?;]", text)
tokens[:5]
# ['the', 'fool', 'doth', 'think', 'he']
chain = MarkovChain(tokens)
def generate_sentences(chain, n=2, length=(10, 20)):
 for _ in range(n):
 l = random.randint(length[0], length[1])
 nonsense = ' '.join(chain.next(n=l))
 print(nonsense)
generate_sentences(chain)
# and unless by some are fascinated by the hour upon the wind faithful
# those that hath had a very much as flaws go

Install

pip install -U marc