Explain how a sequential model (Dense Layer) be built in Tensorflow using Python

Tensorflow is a machine learning framework that is provided by Google. It is an open−source framework used in conjunction with Python to implement algorithms, deep learning applications and much more. It is used in research and for production purposes.

The ‘tensorflow’ package can be installed on Windows using the below line of code −

pip install tensorflow

The layers API is parth of Keras API. Keras means ‘horn’ in Greek. Keras was developed as a part of research for the project ONEIROS (Open ended Neuro-Electronic Intelligent Robot Operating System). Keras is a deep learning API, which is written in Python. It is a high-level API that has a productive interface that helps solve machine learning problems. It runs on top of Tensorflow framework. It was built to help experiment in a quick manner. It provides essential abstractions and building blocks that are essential in developing and encapsulating machine learning solutions. It is highly scalable, and comes with cross platform abilities. This means Keras can be run on TPU or clusters of GPUs. Keras models can also be exported to run in a web browser or a mobile phone as well.

Keras is already present within the Tensorflow package. It can be accessed using the below line of code.

import tensorflow
from tensorflow import keras

We are using the Google Colaboratory to run the below code. Google Colab or Colaboratory helps run Python code over the browser and requires zero configuration and free access to GPUs (Graphical Processing Units). Colaboratory has been built on top of Jupyter Notebook.

Following is the code to create dense layers −


print("Three dense layers are being created")
layer1 = layers.Dense(2, activation="relu", name="layer_1")
layer2 = layers.Dense(3, activation="relu", name="layer_2")
layer3 = layers.Dense(4, name="layer_3")

print("The model is being called on test data")

x = tf.ones((4, 4))
y = layer3(layer2(layer1(x)))

Code credit −  https://www.tensorflow.org/guide/keras/sequential_model


Three dense layers are being created
The model is being called on test data
The layers are
[<tensorflow.python.keras.layers.core.Dense object at 0x7fe921aaf7b8>, <tensorflow.python.keras.layers.core.Dense object at 0x7fe921a6d898>, <tensorflow.python.keras.layers.core.Dense object at 0x7fe921a6dc18>]


  • This is an alternate method to create a sequential model in Keras using Python and adding layers to it.

  • Every layer is created explicity by calling the ‘layers.Dense’ method on it.

  • A sequential model is created by passing a list of layers to this constructor.

  • The ‘layers’ attribute can be used to know more details about the layers in the model.

  • Once the layers have been added, the data is displayed on the console.