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Keras Models

Try in a Colab Notebook here โ†’

Use Weights & Biases for machine learning experiment tracking, dataset versioning, and project collaboration.

Weights & Biases

This colab notebook introduces the WandbModelCheckpoint callback. Use this callback to log your model checkpoints to Weight and Biases Artifacts.

๐ŸŒด Setup and Installation

First, let us install the latest version of Weights and Biases. We will then authenticate this colab instance to use W&B.

!pip install -qq -U wandb
import os
import tensorflow as tf
from tensorflow.keras import layers
from tensorflow.keras import models
import tensorflow_datasets as tfds

# Weights and Biases related imports
import wandb
from wandb.integration.keras import WandbMetricsLogger
from wandb.integration.keras import WandbModelCheckpoint

If this is your first time using W&B or you are not logged in, the link that appears after running wandb.login() will take you to sign-up/login page. Signing up for a free account is as easy as a few clicks.


๐ŸŒณ Hyperparameters

Use of proper config system is a recommended best practice for reproducible machine learning. We can track the hyperparameters for every experiment using W&B. In this colab we will be using simple Python dict as our config system.

configs = dict(
num_classes = 10,
shuffle_buffer = 1024,
batch_size = 64,
image_size = 28,
image_channels = 1,
earlystopping_patience = 3,
learning_rate = 1e-3,
epochs = 10

๐Ÿ Dataset

In this colab, we will be using CIFAR100 dataset from TensorFlow Dataset catalog. We aim to build a simple image classification pipeline using TensorFlow/Keras.

train_ds, valid_ds = tfds.load('fashion_mnist', split=['train', 'test'])

def parse_data(example):
# Get image
image = example["image"]
# image = tf.image.convert_image_dtype(image, dtype=tf.float32)

# Get label
label = example["label"]
label = tf.one_hot(label, depth=configs["num_classes"])

return image, label

def get_dataloader(ds, configs, dataloader_type="train"):
dataloader =, num_parallel_calls=AUTOTUNE)

if dataloader_type=="train":
dataloader = dataloader.shuffle(configs["shuffle_buffer"])

dataloader = (

return dataloader
trainloader = get_dataloader(train_ds, configs)
validloader = get_dataloader(valid_ds, configs, dataloader_type="valid")

๐ŸŽ„ Model

def get_model(configs):
backbone = tf.keras.applications.mobilenet_v2.MobileNetV2(weights='imagenet', include_top=False)
backbone.trainable = False

inputs = layers.Input(shape=(configs["image_size"], configs["image_size"], configs["image_channels"]))
resize = layers.Resizing(32, 32)(inputs)
neck = layers.Conv2D(3, (3,3), padding="same")(resize)
preprocess_input = tf.keras.applications.mobilenet.preprocess_input(neck)
x = backbone(preprocess_input)
x = layers.GlobalAveragePooling2D()(x)
outputs = layers.Dense(configs["num_classes"], activation="softmax")(x)

return models.Model(inputs=inputs, outputs=outputs)
model = get_model(configs)

๐ŸŒฟ Compile Model

optimizer = "adam",
loss = "categorical_crossentropy",
metrics = ["accuracy", tf.keras.metrics.TopKCategoricalAccuracy(k=5, name='top@5_accuracy')]

๐ŸŒป Train

# Initialize a W&B run
run = wandb.init(
project = "intro-keras",
config = configs

# Train your model
epochs = configs["epochs"],
validation_data = validloader,
callbacks = [
WandbModelCheckpoint(filepath="models/") # Notice the use of WandbModelCheckpoint here

# Close the W&B run
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