eliminate use of __file__ in boto3.session

boto3/session.py

@@ -12,7 +12,7 @@
 # language governing permissions and limitations under the License.
 
 import copy
-import os
+from importlib.resources import path
 
 import botocore.session
 from botocore.client import Config
@@ -127,9 +127,9 @@ def _setup_loader(self):
         Setup loader paths so that we can load resources.
         """
         self._loader = self._session.get_component('data_loader')
-        self._loader.search_paths.append(
-            os.path.join(os.path.dirname(__file__), 'data')
-        )
+        # NOTE: this context manager is leaked, there's no good place to clean it up
+        data_path = path(__package__, "data").__enter__()
+        self._loader.search_paths.append(str(data_path))
 
     def get_available_services(self):
         """

tests/functional/test_session.py

@@ -10,6 +10,9 @@
 # distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
 # ANY KIND, either express or implied. See the License for the specific
 # language governing permissions and limitations under the License.
+from importlib.resources import path
+from unittest.mock import patch
+
 import boto3.session
 from tests import unittest
 
@@ -45,3 +48,9 @@ def test_get_available_regions(self):
         regions = self.session.get_available_regions('s3')
         assert isinstance(regions, list)
         assert regions
+
+    def test_loader_search_path(self):
+        with patch.object(boto3.session, '__file__', None):
+            session = boto3.session.Session()
+            with path(boto3, "data") as data_path:
+                assert str(data_path) in session._loader.search_paths