Initialize SDK

Use the instantiate method to initialize the Python SDK and instantiate an instance of the Optimizely client class that exposes API methods like the Decide methods. Each client corresponds to the datafile representing the state of a project for a certain environment.

Version

SDK v3.2.0 and higher

Description

The constructor accepts a configuration object to configure Optimizely Feature Experimentation.

Some parameters are optional because the SDK provides a default implementation, but you may want to override these for your production environments. For example, you may want to override these to set up an error handler and logger to catch issues, an event dispatcher to manage network calls, and a User Profile Service to ensure sticky bucketing.

Parameters

The table below lists the required and optional parameters in Python.

Returns

Instantiates an instance of the Optimizely Feature Experimentation class.

Examples

In the Python SDK, you can provide either sdkKey or datafile or both.

• When initializing with just the SDK key, the SDK will poll for datafile changes in the background at regular intervals.
• When initializing with just the datafile, the SDK will NOT poll for datafile changes in the background.
• When initializing with both the SDK key and datafile, the SDK will use the given datafile and start polling for datafile changes in the background.

Instantiate using SDK Key (recommended)

In the Python SDK, you only need to pass the SDK key value to instantiate a client. Whenever the experiment configuration changes, the SDK handles the change for you.

Include sdkKey as a string property in the options object you pass to the createInstance method.

When you provide the sdkKey, the SDK instance downloads the datafile associated with that sdkKey. When the download completes, the SDK instance updates itself to use the downloaded datafile.

from optimizely import optimizely
from optimizely.config_manager import PollingConfigManager
 
sdk_key = '123456'
conf_manager = PollingConfigManager(
   sdk_key = sdk_key,
   update_interval=10,
)
 
optimizely = optimizely.Optimizely(config_manager=conf_manager)

Instantiate using datafile

You can also instantiate with a hard-coded datafile. If you do not pass in an SDK key, the Optimizely Client will not automatically sync newer versions of the datafile. Any time you retrieve an updated datafile, just re-instantiate the same client.

For simple applications, all you need to provide to instantiate a client is a datafile specifying the project configuration for a given environment. For most advanced implementations, you'll want to customize the logger or error handler for your specific requirements.

from optimizely import optimizely

# Instantiate an Optimizely client
optimizely = optimizely.Optimizely(datafile)

Notes

Enable JSON schema validation

Skipping JSON schema validation enhances performance during instantiation. In the Python SDK, you have control over whether to validate the JSON schema of the datafile when instantiating the client. This example shows how to skip JSON schema validation:

# Skip JSON schema validation (SDK versions 0.1.1 and above)
optimizely = optimizely.Optimizely(datafile,
                                          skip_json_validation=True)

Use authenticated datafiles in secure environments

📘

Note

Authenticated datafiles is in beta. Contact your Customer Success Manager if you are interested in becoming an early user of authenticated datafiles as part of the beta secure environment feature.

You can fetch the Optimizely Feature Experimentation datafile from an authenticated endpoint using a server-side (only) Optimizely Feature Experimentation SDK. To use an authenticated datafile, download your Optimizely Feature Experimentation environment's access token from the Optimizely app at Settings>Environments. Select your secure environment, and copy the Datafile access token. The example below shows how to initialize the Optimizely client using an access token and sdk_key, enabling the client to fetch the authenticated datafile and complete initialization.

# fetch the datafile from an authenticated endpoint
access_tkn = '<YOUR_DATAFILE_ACCESS_TOKEN>'
sdk_key = '<YOUR_SDK_KEY>'
optimizely = optimizely.Optimizely(sdk_key = sdk_key,
                                          datafile_access_token = access_tkn )

For more information on the custom use of the Optimizely Feature Experimentation datafile, see Manage config (datafile).

Source files

The language/platform source files containing the implementation for Python are at optimizely.py.