How to run an AB Test in Python

Step 1: Create a Basic Python Web Server

First, you’ll need a simple Python web server. Flask is a lightweight WSGI web application framework that’s perfect for this purpose.

Step 1: Creating a Simple Python “Hello World” Application

1. Set Up Your Python Environment:
   • Ensure Python is installed on your system. You can download it from python.org.
   • Optionally, create a virtual environment for your project to manage dependencies:

   python -m venv venv
   source venv/bin/activate  # On Windows use `venv\Scripts\activate`
   

2. Create a New Python File:
   • In your project directory, create a file named app.py.
3. Write a Simple Python Program:
   • Open app.py in your favorite text editor or IDE and write a simple Python program:

   print("Hello, World!")
   

4. Run Your Program:
   • Run your program from the command line or terminal:

   python app.py
   

   • You should see “Hello, World!” printed to the console.

Step 2: Integrate Statsig for A/B Testing

1. Install Statsig SDK:
   • Add the Statsig SDK to your project:

   pip install statsig
   

2. Initialize Statsig in Your Application:
   • Modify app.py to include initialization of the Statsig SDK and to check a feature flag. You will need a server secret key from Statsig, which you can get from the Statsig dashboard.

   from statsig import statsig
   from statsig.statsig_user import StatsigUser
   # Initialize Statsig with your server secret key
   statsig.initialize('your_server_secret_key')
   user = StatsigUser(
     user_id = "user123",
     email = "[e-mail]",
   )  # Customize user info as needed
   experiment = statsig.get_experiment(user, 'your_experiment_name')
   text_to_show = experiment.get('text', 'Hello, World!')
   print(text_to_show)
   # Shutdown Statsig before your application exits
   statsig.shutdown()
   

   • Replace 'your_server_secret_key' with your actual server secret key from Statsig.
   • Replace 'your_experiment_name' with the name of your experiment.

Step 3: Creating the A/B Test in Statsig Console

1. Log Into Statsig Console:
   • Access the Statsig Console and sign in.
2. Create an Experiment:
   • Navigate to the “Experiments” section and click “Create New”.
   • Fill in the experiment details, including a unique key for 'your_experiment_name'.
3. Configure Experiment Variants:
   • Define your variants, for example, variant_a and variant_b.
   • Add a parameter called 'text' for each variant and configure the text you wish to display, such as “This is Control Variant” and “This is Test Variant”.
4. Launch Your Experiment:
   • After setting up your variants and their parameters, save your configurations and start the experiment.

By following these steps, you’ve set up a Python Flask application that utilizes Statsig for running an A/B test, dynamically serving different text content based on the experiment’s variant. This setup enables data-driven decisions and iterative improvements based on user interactions.