[PYTHON] I tried to make something like a chatbot with the Seq2Seq model of TensorFlow

I'm studying TensorFlow and want to make something Sequence-to-Sequence Models Chat at the end It was written that you can make bots, so I made it by referring to the tutorial code. In particular, I referred to I made a conversation AI with TensorFlow. Click here for github (https://github.com/sanshirookazaki/chat)

Execution environment

-OS　X -TensorFlow r0.9

File

The file is as follows

Data preparation

The contents of the datas folder are as follows. Chat transmission is IN and reply is OUT. Put the necessary data in the above four files, and prepare the rest empty.

Data contents

I couldn't find a lot of conversation data, so I morphologically analyzed the conversation in a junior high school English textbook with Mecab and inserted it with line breaks.

Outgoing

train_data_in.txt

Are you from New York? ..
・
・
・

reply

train_data_out.txt

No, it's not. I'm from Boston.
・
・
・

It feels like. Prepare this for test_data_in.txt and test_data_out.txt as well. There are 306 sentences for training and 306 sentences for testing (153 each for IN and OUT), for a total of 712 sentences, and the number of vocabulary is about 500 each for training and testing. There is very little data (crying)

Learning code

This is the code for learning. By default in the tutorial, the batch (batch_size) was 64, the number of layers (num_layers) was 3, the unit of layers (size) was 1024, and the number of vocabularies (vocab_size) was 40,000.

translate.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import math
import os
import random
import sys
import time

import tensorflow.python.platform

import numpy as np
from six.moves import xrange  
import tensorflow as tf

import data_utils
from tensorflow.models.rnn.translate import seq2seq_model
from tensorflow.python.platform import gfile


tf.app.flags.DEFINE_float("learning_rate", 0.5, "Learning rate.")
tf.app.flags.DEFINE_float("learning_rate_decay_factor", 0.99,
                          "Learning rate decays by this much.")
tf.app.flags.DEFINE_float("max_gradient_norm", 5.0,
                          "Clip gradients to this norm.")
tf.app.flags.DEFINE_integer("batch_size", 4,
                            "Batch size to use during training.")
tf.app.flags.DEFINE_integer("size", 256, "Size of each model layer.")
tf.app.flags.DEFINE_integer("num_layers", 2, "Number of layers in the model.")
tf.app.flags.DEFINE_integer("in_vocab_size", 500, "input vocabulary size.")
tf.app.flags.DEFINE_integer("out_vocab_size", 500, "output vocabulary size.")
tf.app.flags.DEFINE_string("data_dir", "datas", "Data directory")       
tf.app.flags.DEFINE_string("train_dir", "datas", "Training directory.")
tf.app.flags.DEFINE_integer("max_train_data_size", 0,
                            "Limit on the size of training data (0: no limit).")
tf.app.flags.DEFINE_integer("steps_per_checkpoint", 100,
                            "How many training steps to do per checkpoint.")
tf.app.flags.DEFINE_boolean("decode", False,
                            "Set to True for interactive decoding.")
tf.app.flags.DEFINE_boolean("self_test", False,
                            "Run a self-test if this is set to True.")

FLAGS = tf.app.flags.FLAGS

_buckets = [(5, 10), (10, 15), (20, 25), (40, 50)]


def read_data(source_path, target_path, max_size=None):
  data_set = [[] for _ in _buckets]
  source_file = open(source_path,"r")
  target_file = open(target_path,"r")

  source, target = source_file.readline(), target_file.readline()     
  counter = 0
  while source and target and (not max_size or counter < max_size):
    counter += 1
    if counter % 50 == 0:                         
      print("  reading data line %d" % counter)
      sys.stdout.flush()

    source_ids = [int(x) for x in source.split()]   
    target_ids = [int(x) for x in target.split()]    
    target_ids.append(data_utils.EOS_ID)             
    for bucket_id, (source_size, target_size) in enumerate(_buckets):        
      if len(source_ids) < source_size and len(target_ids) < target_size:    
        data_set[bucket_id].append([source_ids, target_ids])                 
        break
    source, target = source_file.readline(), target_file.readline()
  return data_set

def create_model(session, forward_only):
  model = seq2seq_model.Seq2SeqModel(
      FLAGS.in_vocab_size, FLAGS.out_vocab_size, _buckets,                           
      FLAGS.size, FLAGS.num_layers, FLAGS.max_gradient_norm, FLAGS.batch_size,      
      FLAGS.learning_rate, FLAGS.learning_rate_decay_factor,                       
      forward_only=forward_only)                                                    
  
  ckpt = tf.train.get_checkpoint_state(FLAGS.train_dir)                             
  if ckpt and gfile.Exists(ckpt.model_checkpoint_path):                              
    print("Reading model parameters from %s" % ckpt.model_checkpoint_path)          
    model.saver.restore(session, ckpt.model_checkpoint_path)                        
  else:
    print("Created model with fresh parameters.")
    session.run(tf.initialize_all_variables())                                      
  return model                                                                      


def train():
                                                                                    
  print("Preparing data in %s" % FLAGS.data_dir)                                
  in_train, out_train, in_dev, out_dev, _, _ = data_utils.prepare_wmt_data(           
      FLAGS.data_dir, FLAGS.in_vocab_size, FLAGS.out_vocab_size)                     
                                                  

  with tf.Session() as sess:
    

    print("Creating %d layers of %d units." % (FLAGS.num_layers, FLAGS.size))       
    model = create_model(sess, False)                                               

    print ("Reading development and training data (limit: %d)."     
           % FLAGS.max_train_data_size)                                             
    dev_set = read_data(in_dev, out_dev)                                             
    train_set = read_data(in_train, out_train, FLAGS.max_train_data_size)            
                                                                                    
    train_bucket_sizes = [len(train_set[b]) for b in xrange(len(_buckets))]         
    train_total_size = float(sum(train_bucket_sizes))                               

 
    train_buckets_scale = [sum(train_bucket_sizes[:i + 1]) / train_total_size     
                           for i in xrange(len(train_bucket_sizes))]              

    step_time, loss = 0.0, 0.0
    current_step = 0
    previous_losses = []
    while True:
     
      random_number_01 = np.random.random_sample()                     
      bucket_id = min([i for i in xrange(len(train_buckets_scale))      
                       if train_buckets_scale[i] > random_number_01])

      start_time = time.time()
      encoder_inputs, decoder_inputs, target_weights = model.get_batch(   
          train_set, bucket_id)                                           
                                                                          
      _, step_loss, _ = model.step(sess, encoder_inputs, decoder_inputs, 
                                   target_weights, bucket_id, False)      
      step_time += (time.time() - start_time) / FLAGS.steps_per_checkpoint
      loss += step_loss / FLAGS.steps_per_checkpoint
      current_step += 1

      
      if current_step % FLAGS.steps_per_checkpoint == 0:
     
        perplexity = math.exp(loss) if loss < 300 else float('inf')
        print ("global step %d learning rate %.4f step-time %.2f perplexity "
               "%.2f" % (model.global_step.eval(), model.learning_rate.eval(),
                         step_time, perplexity))


        if len(previous_losses) > 2 and loss > max(previous_losses[-3:]):
          sess.run(model.learning_rate_decay_op)
        previous_losses.append(loss)

        checkpoint_path = os.path.join(FLAGS.train_dir, "translate.ckpt")
        model.saver.save(sess, checkpoint_path, global_step=model.global_step)
        step_time, loss = 0.0, 0.0

        for bucket_id in xrange(len(_buckets)):
          encoder_inputs, decoder_inputs, target_weights = model.get_batch(
              dev_set, bucket_id)
          _, eval_loss, _ = model.step(sess, encoder_inputs, decoder_inputs,
                                       target_weights, bucket_id, True)
          eval_ppx = math.exp(eval_loss) if eval_loss < 300 else float('inf')
          print("  eval: bucket %d perplexity %.2f" % (bucket_id, eval_ppx))
        sys.stdout.flush()


def decode():
  with tf.Session() as sess:
    print ("Hello!!")
    model = create_model(sess, True)                         
    model.batch_size = 1  
    
    in_vocab_path = os.path.join(FLAGS.data_dir,
                                 "vocab_in.txt")     
    out_vocab_path = os.path.join(FLAGS.data_dir,
                                 "vocab_out.txt" )
                                                                        
    in_vocab, _ = data_utils.initialize_vocabulary(in_vocab_path)        
    _, rev_out_vocab = data_utils.initialize_vocabulary(out_vocab_path)    

    
    sys.stdout.write("> ")
    sys.stdout.flush()
    sentence = sys.stdin.readline()    
    while sentence:

      token_ids = data_utils.sentence_to_token_ids(sentence, in_vocab)   
      
      bucket_id = min([b for b in xrange(len(_buckets))
                       if _buckets[b][0] > len(token_ids)])               

      encoder_inputs, decoder_inputs, target_weights = model.get_batch(
          {bucket_id: [(token_ids, [])]}, bucket_id)
    
      _, _, output_logits = model.step(sess, encoder_inputs, decoder_inputs,      
                                       target_weights, bucket_id, True)

      outputs = [int(np.argmax(logit, axis=1)) for logit in output_logits]       

      if data_utils.EOS_ID in outputs:
        outputs = outputs[:outputs.index(data_utils.EOS_ID)]                      

      print(" ".join([rev_out_vocab[output] for output in outputs]))
      print("> ", end="")
      sys.stdout.flush()
      sentence = sys.stdin.readline()                                             
                                                                                  

def self_test():
  
  with tf.Session() as sess:
    print("Self-test for neural translation model.")
    
    model = seq2seq_model.Seq2SeqModel(10, 10, [(3, 3), (6, 6)], 32, 2,
                                       5.0, 32, 0.3, 0.99, num_samples=8)
    sess.run(tf.initialize_all_variables())

    
    data_set = ([([1, 1], [2, 2]), ([3, 3], [4]), ([5], [6])],
                [([1, 1, 1, 1, 1], [2, 2, 2, 2, 2]), ([3, 3, 3], [5, 6])])
    for _ in xrange(5):  
      bucket_id = random.choice([0, 1])
      encoder_inputs, decoder_inputs, target_weights = model.get_batch(
          data_set, bucket_id)
      model.step(sess, encoder_inputs, decoder_inputs, target_weights,
                 bucket_id, False)


def main(_):
  if FLAGS.self_test:
    self_test()
  elif FLAGS.decode:
    decode()
  else:
    train()

if __name__ == "__main__":
  tf.app.run()

Run

python translate.py --data_dir datas --train_dir datas

When you type, learning starts and the checkpoints are saved in the data.

Creating 2 layers of 256 units.
Created model with fresh parameters.
Reading development and training data (limit: 0).
  reading data line 50
  reading data line 100
  reading data line 150
  reading data line 50
  reading data line 100
  reading data line 150
global step 100 learning rate 0.5000 step-time 0.77 perplexity 137.46
  eval: bucket 0 perplexity 90.26
  eval: bucket 1 perplexity 176.55
  eval: bucket 2 perplexity 203.59
  eval: bucket 3 perplexity 211.34
global step 200 learning rate 0.5000 step-time 0.73 perplexity 53.88
  eval: bucket 0 perplexity 64.65
  eval: bucket 1 perplexity 161.62
  eval: bucket 2 perplexity 108.95
  eval: bucket 3 perplexity 213.13
　　　　　　　　　　　　　　　　　　　　　　　　　　　　：
　　　　　　　　　　　　　　　　　　　　　　　　　　　　：

Learning progresses like this, and convergence is slow, so round up at an appropriate place,

python translate.py --decode --data_dir datas --train_dir datas

Type to enter interactive mode.

For the time being, I tried it around step1000. > Is the input.

It's not a conversation at all (laughs) The same words will be returned. Is this area due to the lack of data?

Also as before

python translate.py --data_dir datas --train_dir datas

If you hit, you will learn from the continuation.

Summary

There was too little data to make a conversation.