Port of Joel Grus Fizz Buzz in Tensorflow to Keras

fizzbuzz.py

from keras.models import Sequential
from keras.layers import Dense
import numpy as np

np.random.seed(7)

NUM_DIGITS = 12

def binary_encode(i, num_digits):
    return np.array([i >> d & 1 for d in range(num_digits)])

def fizz_buzz_encode(i):
    if   i % 15 == 0: return np.array([0, 0, 0, 1])
    elif i % 5  == 0: return np.array([0, 0, 1, 0])
    elif i % 3  == 0: return np.array([0, 1, 0, 0])
    else:             return np.array([1, 0, 0, 0])

def fizz_buzz(i, prediction):
    return [str(i), "fizz", "buzz", "fizzbuzz"][prediction]

X = np.array([binary_encode(i, NUM_DIGITS) for i in range(101, 2 ** NUM_DIGITS)])
Y = np.array([fizz_buzz_encode(i)          for i in range(101, 2 ** NUM_DIGITS)])

model = Sequential()
model.add(Dense(NUM_DIGITS, input_dim=NUM_DIGITS, activation='relu'))
model.add(Dense(100, activation='relu'))
model.add(Dense(4, activation='softmax'))
model.compile(loss='categorical_crossentropy', optimizer='rmsprop', metrics=['accuracy'])
model.fit(X, Y, epochs=2000, batch_size=128)

scores = model.evaluate(X, Y)
print("\n%s: %.2f%%" % (model.metrics_names[1], scores[1]*100))

numbers = np.arange(1, 101)
X2 = np.transpose(binary_encode(numbers, NUM_DIGITS))

predictions = model.predict_classes(X2)
output = np.vectorize(fizz_buzz)(numbers, predictions)
print(output)