Botocore Events

Botocore will emit events during various parts of its execution. Users of the library can register handlers (callables) for these events, such that whenever an event is emitted, all registered handlers for the event will be called. This allows you to customize and extend the behavior of botocore without having to modify the internals. This document covers this event system in detail.

Session Events

The main interface for events is through the botocore.session.Session class. The Session object allows you to register and unregister handlers to events.

Event Types

The table below shows all of the events emitted by botocore. In some cases, the events are listed as <service>.<operations>.bar, in which <service> and <operation> are replaced with a specific service and operation, for example

Event Name Occurance Arguments Return Value
service-created Whenever a service is created via the Sessions get_service method. service - The newly created botocore.service.Service object. Ignored.
before-call.<service>.<operation> When an operation is being called ( operation - The newly created botocore.operation.Operation object. Ignored.
after-call.<service>.<operation> After an operation has been called, but before the response is parsed. http_response - The HTTP response, parsed - The parsed data. Ignored.

Event Emission

When an event is emitted, the handlers are invoked in the order that they were registered.