This Flask extension provides the ability to create feature flags in your code.

This allows you to selectively enable or disable features (for instance, enabled in development, disabled in production), or for admins of the site.

from flask.ext.feature import FeatureManager
feature = FeatureManager(app)

Alternatively, you can configure it with the factory pattern:

feature = FeatureManager()
feature.init_app(app)

Flask-Feature relies on a dictionary in the application's configuration in order to determine whether or not a feature is enabled.

Example:

app.config['FEATURES'] = {
    'test_key': True
}

As of now, the possible values for a key are: True, False, and 'admin'. If your key is set to 'admin', a function must be defined on your user object named is_admin(), which returns True if the given user is an admin, and False otherwise. If the user is an admin, and the feature is set to 'admin', is_enabled() will return True. Otherwise, it will return False.

There are future plans to allow whitelisting users, percentage based rampups, but they are not implemented as of now.

You can access feature information via the feature object on your app, like so:

app.feature.is_enabled('test_key') # This returns True

Additionally, by default, the feature manager registers a context processor for use in templates:

{% if feature.is_enabled('test_key') %}
    ...
{% endif %}