The Planet SDK for Python is Version 2 of what was previously referred to as the Planet API client.

Version 2 is essentially a complete rewrite and brings with it big changes to the Python library.

In Version 1, a single client was created for all APIs, client=api.ClientV1(api_key=API_KEY). With this client, all commumication was synchronous. Asynchronous bulk support was provided with the downloader module. There was no built-in support for polling when an order was ready to download or tracking when an order was downloaded.

In Version 2, a Session is used to manage all communication with the Planet APIs. This provides for multiple asynchronous connections. An API-specific client is created. This client manages polling and downloading, along with any other capabilities provided by the API.