[ENH] move utils module to folder (#1612)

This is a minimal refactor preparatory PR.

It changes the `utils` module from a file to a folder, in anticipation
of other PR that may add further utils - to avoid that everyone works on
the same file.

Author: fkiraly

openml/utils/__init__.py

@@ -0,0 +1,39 @@
+"""Utilities module."""
+
+from openml.utils._openml import (
+    ProgressBar,
+    ReprMixin,
+    _create_cache_directory,
+    _create_cache_directory_for_id,
+    _create_lockfiles_dir,
+    _delete_entity,
+    _get_cache_dir_for_id,
+    _get_cache_dir_for_key,
+    _get_rest_api_type_alias,
+    _list_all,
+    _remove_cache_dir_for_id,
+    _tag_entity,
+    _tag_openml_base,
+    extract_xml_tags,
+    get_cache_size,
+    thread_safe_if_oslo_installed,
+)
+
+__all__ = [
+    "ProgressBar",
+    "ReprMixin",
+    "_create_cache_directory",
+    "_create_cache_directory_for_id",
+    "_create_lockfiles_dir",
+    "_delete_entity",
+    "_get_cache_dir_for_id",
+    "_get_cache_dir_for_key",
+    "_get_rest_api_type_alias",
+    "_list_all",
+    "_remove_cache_dir_for_id",
+    "_tag_entity",
+    "_tag_openml_base",
+    "extract_xml_tags",
+    "get_cache_size",
+    "thread_safe_if_oslo_installed",
+]

openml/utils.py openml/utils/_openml.pyopenml/utils.py renamed to openml/utils/_openml.py

@@ -26,8 +26,7 @@
 import openml
 import openml._api_calls
 import openml.exceptions
-
-from . import config
+from openml import config
 
 # Avoid import cycles: https://mypy.readthedocs.io/en/latest/common_issues.html#import-cycles
 if TYPE_CHECKING: