module level import for _backend

Author: geetu040

openml/__init__.py

@@ -33,7 +33,7 @@
     utils,
 )
 from .__version__ import __version__
-from ._api.setup._instance import _backend
+from ._api import _backend
 from .datasets import OpenMLDataFeature, OpenMLDataset
 from .evaluations import OpenMLEvaluation
 from .flows import OpenMLFlow

openml/_api/__init__.py

@@ -33,6 +33,7 @@
     CacheConfig,
     Config,
     ConnectionConfig,
+    _backend,
 )
 
 __all__ = [
@@ -66,4 +67,5 @@
     "StudyV2API",
     "TaskV1API",
     "TaskV2API",
+    "_backend",
 ]

openml/_api/setup/__init__.py

@@ -1,3 +1,4 @@
+from ._instance import _backend
 from .backend import APIBackend
 from .builder import APIBackendBuilder
 from .config import APIConfig, CacheConfig, Config, ConnectionConfig
@@ -9,4 +10,5 @@
     "CacheConfig",
     "Config",
     "ConnectionConfig",
+    "_backend",
 ]

openml/_api/setup/_utils.py

@@ -0,0 +1,49 @@
+from __future__ import annotations
+
+import logging
+import os
+import platform
+from pathlib import Path
+
+openml_logger = logging.getLogger("openml")
+
+# Default values (see also https://github.com/openml/OpenML/wiki/Client-API-Standards)
+_user_path = Path("~").expanduser().absolute()
+
+
+def _resolve_default_cache_dir() -> Path:
+    user_defined_cache_dir = os.environ.get("OPENML_CACHE_DIR")
+    if user_defined_cache_dir is not None:
+        return Path(user_defined_cache_dir)
+
+    if platform.system().lower() != "linux":
+        return _user_path / ".openml"
+
+    xdg_cache_home = os.environ.get("XDG_CACHE_HOME")
+    if xdg_cache_home is None:
+        return Path("~", ".cache", "openml")
+
+    # This is the proper XDG_CACHE_HOME directory, but
+    # we unfortunately had a problem where we used XDG_CACHE_HOME/org,
+    # we check heuristically if this old directory still exists and issue
+    # a warning if it does. There's too much data to move to do this for the user.
+
+    # The new cache directory exists
+    cache_dir = Path(xdg_cache_home) / "openml"
+    if cache_dir.exists():
+        return cache_dir
+
+    # The old cache directory *does not* exist
+    heuristic_dir_for_backwards_compat = Path(xdg_cache_home) / "org" / "openml"
+    if not heuristic_dir_for_backwards_compat.exists():
+        return cache_dir
+
+    root_dir_to_delete = Path(xdg_cache_home) / "org"
+    openml_logger.warning(
+        "An old cache directory was found at '%s'. This directory is no longer used by "
+        "OpenML-Python. To silence this warning you would need to delete the old cache "
+        "directory. The cached files will then be located in '%s'.",
+        root_dir_to_delete,
+        cache_dir,
+    )
+    return Path(xdg_cache_home)