import nltk

def decode_review(review):
    tokens = ['<START>'] + nltk.tokenize.wordpunct_tokenize(review)
    indices = np.array([word_index[word] if (word in word_index and word_index[word] < 10000) else word_index['<UNK>'] for word in tokens])
    return indices


review = "This isn't just a beautifully crafted gangster film. Or an outstanding family portrait, for that matter. An amazing period piece. A character study. A lesson in filmmaking and an inspiration to generations of actors, directors, screenwriters and producers. For me, this is more: this is the definitive film. 10 stars out of 10."

indices = decode_review(review)

sequence = keras.preprocessing.sequence.pad_sequences([indices],
                                                      value=word_index["<PAD>"],
                                                      padding='post',
                                                      maxlen=256)

model.predict_proba(sequence)