Python Basics#

This tutorial is a quick introduction to training and testing your model with Vowpal Wabbit using Python. We explore passing some data to Vowpal Wabbit to learn a model and get a prediction.

For more advanced Vowpal Wabbit tutorials, including how to format data and understand results, see Tutorials.

Prerequisites

To install Vowpal Wabbit see Get Started.

Getting started#

First, import the Vowpal Wabbit Python package for this tutorial:

import vowpalwabbit

Next, we create an instance of Vowpal Wabbit, and pass the quiet=True option to avoid diagnostic information output to stdout location:

model = vowpalwabbit.Workspace(quiet=True)

Training scenario and dataset#

For this tutorial scenario, we want Vowpal Wabbit to help us predict whether or not our house will require a new roof in the next 10 years.

To create some examples, we use the Vowpal Wabbit text format and then learn on them:

train_examples = [
    "0 | price:.23 sqft:.25 age:.05 2006",
    "1 | price:.18 sqft:.15 age:.35 1976",
    "0 | price:.53 sqft:.32 age:.87 1924",
]

for example in train_examples:
    model.learn(example)

Note: For more details on Vowpal Wabbit input format and feature hashing techniques see the Linear Regression Tutorial.

Now, we create a test_example to use for prediction:

test_example = "| price:.46 sqft:.4 age:.10 1924"

prediction = model.predict(test_example)
print(prediction)

0.0

Vowpal Wabbit results#

The model predicted a value of 0. According to our learning model, our house will not need a new roof in the next 10 years (at least that is the result from just three examples we used in our training dataset).

More to explore#

  • To learn how to approach a contextual bandits problem using Vowpal Wabbit — including how to work with different contextual bandits approaches, how to format data, and understand the results — see the Contextual Bandit Reinforcement Learning Tutorial.

  • For more on the contextual bandits approach to reinforcement learning, including a content personalization scenario, see the Contextual Bandit Simulation Tutorial.

  • See the Linear Regression Tutorial for a different look at the roof replacement problem and learn more about Vowpal Wabbit’s format and understanding the results.