use of keras in python code example

Example 1: keras ann code

import numpy as np
from keras.utils import to_categorical
from keras import models
from keras import layers
from keras.datasets import imdb
(training_data, training_targets), (testing_data, testing_targets) = imdb.load_data(num_words=10000)
data = np.concatenate((training_data, testing_data), axis=0)
targets = np.concatenate((training_targets, testing_targets), axis=0)
def vectorize(sequences, dimension = 10000):
 results = np.zeros((len(sequences), dimension))
 for i, sequence in enumerate(sequences):
  results[i, sequence] = 1
 return results
 
data = vectorize(data)
targets = np.array(targets).astype("float32")
test_x = data[:10000]
test_y = targets[:10000]
train_x = data[10000:]
train_y = targets[10000:]
model = models.Sequential()
# Input - Layer
model.add(layers.Dense(50, activation = "relu", input_shape=(10000, )))
# Hidden - Layers
model.add(layers.Dropout(0.3, noise_shape=None, seed=None))
model.add(layers.Dense(50, activation = "relu"))
model.add(layers.Dropout(0.2, noise_shape=None, seed=None))
model.add(layers.Dense(50, activation = "relu"))
# Output- Layer
model.add(layers.Dense(1, activation = "sigmoid"))
model.summary()
# compiling the model
model.compile(
 optimizer = "adam",
 loss = "binary_crossentropy",
 metrics = ["accuracy"]
)
results = model.fit(
 train_x, train_y,
 epochs= 2,
 batch_size = 500,
 validation_data = (test_x, test_y)
)
print("Test-Accuracy:", np.mean(results.history["val_acc"]))

Example 2: what is keras

Keras is an open-source software library that provides a Python interface for artificial neural networks. Keras acts as an interface for the TensorFlow library.