20318: Merge branch 'main' into 20318-disk-cache

[arvados.git] / sdk / python / arvados / __init__.py

diff --git a/sdk/python/arvados/__init__.py b/sdk/python/arvados/__init__.py
index 8a7a151ee0d6f63170cf0ce880de3c3e56a573ba..83f658201ca3b8c8100c7a0497744af9f4cb3f49 100644 (file)
--- a/sdk/python/arvados/__init__.py
+++ b/sdk/python/arvados/__init__.py
@@ -1,6 +1,23 @@
 # Copyright (C) The Arvados Authors. All rights reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
+"""Arvados Python SDK
+
+This module provides the entire Python SDK for Arvados. The most useful modules
+include:
+
+* arvados.api - After you `import arvados`, you can call `arvados.api` as a
+  shortcut to the client constructor function `arvados.api.api`.
+
+* arvados.collection - The `arvados.collection.Collection` class provides a
+  high-level interface to read and write collections. It coordinates sending
+  data to and from Keep, and synchronizing updates with the collection object.
+
+* arvados.util - Utility functions to use mostly in conjunction with the API
+  client object and the results it returns.
+
+Other submodules provide lower-level functionality.
+"""
 
 import logging as stdliblog
 import os
@@ -9,15 +26,24 @@ import types
 
 from collections import UserDict
 
-from .api import api, api_from_config, http_cache
+from . import api, errors, util
+from .api import api_from_config, http_cache
 from .collection import CollectionReader, CollectionWriter, ResumableCollectionWriter
 from arvados.keep import *
 from arvados.stream import *
 from .arvfile import StreamFileReader
 from .logging import log_format, log_date_format, log_handler
 from .retry import RetryLoop
-import arvados.errors as errors
-import arvados.util as util
+
+# Previous versions of the PySDK used to say `from .api import api`.  This
+# made it convenient to call the API client constructor, but difficult to
+# access the rest of the `arvados.api` module. The magic below fixes that
+# bug while retaining backwards compatibility: `arvados.api` is now the
+# module and you can import it normally, but we make that module callable so
+# all the existing code that says `arvados.api('v1', ...)` still works.
+class _CallableAPIModule(api.__class__):
+    __call__ = staticmethod(api.api)
+api.__class__ = _CallableAPIModule
 
 # Override logging module pulled in via `from ... import *`
 # so users can `import arvados.logging`.