Merge pull request #52 from Juanets/interactivity

Add interactive mode

Author: minimaxir

README.md

@@ -56,7 +56,23 @@ Kubernetes by Google’s Bern
 ```
 
 You can also train a new model, with support for word level embeddings and bidirectional RNN layers by adding `new_model=True` to any train function.
+ 
+### Interactive mode
+It's also possible to get involved in how the output unfolds, step by step. Interactive mode will suggest you the *top N* options for the next char/word, and allows you to pick one.  
+  
+Just pass `interactive=True` and `top=N`. N defaults to 3.
 
+```python
+from textgenrnn import textgenrnn
+
+textgen = textgenrnn()
+textgen.generate(interactive=True, top_n=5)
+```
+  
+![word_level_demo](/docs/word_level_demo.gif)
+  
+This can add a *human touch* to the output; it feels like you're the writer! ([reference](https://fivethirtyeight.com/features/some-like-it-bot/))
+  
 ## Usage
 
 textgenrnn can be installed [from pypi](https://pypi.python.org/pypi/textgenrnn) via `pip`:
@@ -107,8 +123,6 @@ Additionally, the retraining is done with a momentum-based optimizer and a linea
 
 * A way to visualize the attention-layer outputs to see how the network "learns."
 
-* Supervised text generation mode: allow the model to present the top *n* options and user select the next char/word ([reference](https://fivethirtyeight.com/features/some-like-it-bot/))
-
 * A mode to allow the model architecture to be used for chatbot conversations (may be released as a separate project)
 
 * More depth toward context (positional context + allowing multiple context labels)

docs/word_level_demo.gif

@@ -66,7 +66,8 @@ def __init__(self, weights_path=None,
         self.indices_char = dict((self.vocab[c], c) for c in self.vocab)
 
     def generate(self, n=1, return_as_list=False, prefix=None,
-                 temperature=0.5, max_gen_length=300):
+                 temperature=0.5, max_gen_length=300, interactive=False,
+                 top_n=3):
         gen_texts = []
         for _ in range(n):
             gen_text = textgenrnn_generate(self.model,
@@ -79,7 +80,9 @@ def generate(self, n=1, return_as_list=False, prefix=None,
                                            self.config['word_level'],
                                            self.config.get(
                                                'single_text', False),
-                                           max_gen_length)
+                                           max_gen_length,
+                                           interactive,
+                                           top_n)
             if not return_as_list:
                 print("{}\n".format(gen_text))
             gen_texts.append(gen_text)

textgenrnn/textgenrnn.py

@@ -11,7 +11,7 @@
 import re
 
 
-def textgenrnn_sample(preds, temperature):
+def textgenrnn_sample(preds, temperature, interactive=False, top_n=3):
     '''
     Samples predicted probabilities of the next character to allow
     for the network to show "creativity."
@@ -26,12 +26,18 @@ def textgenrnn_sample(preds, temperature):
     exp_preds = np.exp(preds)
     preds = exp_preds / np.sum(exp_preds)
     probas = np.random.multinomial(1, preds, 1)
-    index = np.argmax(probas)
-
-    # prevent function from being able to choose 0 (placeholder)
-    # choose 2nd best index from preds
-    if index == 0:
-        index = np.argsort(preds)[-2]
+    
+    if not interactive:
+        index = np.argmax(probas)
+
+        # prevent function from being able to choose 0 (placeholder)
+        # choose 2nd best index from preds
+        if index == 0:
+            index = np.argsort(preds)[-2]        
+    else:
+        # return list of top N chars/words
+        # descending order, based on probability
+        index = (-preds).argsort()[:top_n]
 
     return index
 
@@ -41,11 +47,15 @@ def textgenrnn_generate(model, vocab,
                         maxlen=40, meta_token='<s>',
                         word_level=False,
                         single_text=False,
-                        max_gen_length=300):
+                        max_gen_length=300,
+                        interactive=False,
+                        top_n=3):
     '''
     Generates and returns a single text.
     '''
 
+    collapse_char = ' ' if word_level else ''
+    
     # If generating word level, must add spaces around each punctuation.
     # https://stackoverflow.com/a/3645946/9314418
     if word_level and prefix:
@@ -72,15 +82,53 @@ def textgenrnn_generate(model, vocab,
 
     while next_char != meta_token and len(text) < max_gen_length:
         encoded_text = textgenrnn_encode_sequence(text[-maxlen:],
-                                                  vocab, maxlen)
+                                                vocab, maxlen)
         next_temperature = temperature[(len(text) - 1) % len(temperature)]
-        next_index = textgenrnn_sample(
-            model.predict(encoded_text, batch_size=1)[0],
-            next_temperature)
-        next_char = indices_char[next_index]
-        text += [next_char]
 
-    collapse_char = ' ' if word_level else ''
+        if not interactive:
+            # auto-generate text without user intervention
+            next_index = textgenrnn_sample(
+                model.predict(encoded_text, batch_size=1)[0],
+                next_temperature)
+            next_char = indices_char[next_index]
+            text += [next_char]                    
+        else:
+            # ask user what the next char/word should be
+            options_index = textgenrnn_sample(
+                model.predict(encoded_text, batch_size=1)[0],
+                next_temperature,
+                interactive=interactive,
+                top_n=top_n
+            )
+            options = [indices_char[idx] for idx in options_index]
+            print('Controls:\n\ts: stop.\tx: backspace.\to: write your own.')
+            print('\nOptions:')
+
+            for i, option in enumerate(options, 1):
+                print('\t{}: {}'.format(i, option))
+
+            print('\nProgress: {}'.format(collapse_char.join(text)[3:]))
+            print('\nYour choice?')
+            user_input = input('> ')
+
+            try:
+                user_input = int(user_input)
+                next_char = options[user_input-1]
+                text += [next_char]
+            except ValueError:
+                if user_input == 's':
+                    next_char = '<s>'
+                    text += [next_char]
+                elif user_input == 'o':
+                    other = input('> ')
+                    text += [other]                    
+                elif user_input == 'x':
+                    try:
+                        del text[-1]
+                    except IndexError:
+                        pass
+                else:
+                    print('That\'s not an option!')
 
     # if single text, ignore sequences generated w/ padding
     # if not single text, strip the <s> meta_tokens