feat: introduce compatibility with native namespace packages (#706)

* feat: introduce compatibility with native namespace packages

* reformatted with black

* removed pkg_resources

* Moved importlib to extras and resolved issues with using it in tests

* reformatted with black

* Fixed mistake of not checking only first 3 indexes of PANDAS_VERSION

* Fixed another error in comparison strings

* use setuptools.find_namespace_packages()

---------

Co-authored-by: Anthonios Partheniou <partheniou@google.com>

Author: kiraksi

google/__init__.py

@@ -44,7 +44,7 @@
     "protobuf>=3.19.5,<5.0.0dev,!=3.20.0,!=3.20.1,!=4.21.0,!=4.21.1,!=4.21.2,!=4.21.3,!=4.21.4,!=4.21.5",
 ]
 extras = {
-    "pandas": ["pandas>=0.21.1"],
+    "pandas": ["pandas>=0.21.1", "importlib_metadata>=1.0.0; python_version<'3.8'"],
     "fastavro": ["fastavro>=0.21.2"],
     "pyarrow": ["pyarrow>=0.15.0"],
 }
@@ -58,14 +58,10 @@
 
 packages = [
     package
-    for package in setuptools.PEP420PackageFinder.find()
+    for package in setuptools.find_namespace_packages()
     if package.startswith("google")
 ]
 
-namespaces = ["google"]
-if "google.cloud" in packages:
-    namespaces.append("google.cloud")
-
 setuptools.setup(
     name=name,
     version=version,
@@ -92,7 +88,6 @@
     platforms="Posix; MacOS X; Windows",
     packages=packages,
     python_requires=">=3.7",
-    namespace_packages=namespaces,
     install_requires=dependencies,
     extras_require=extras,
     scripts=["scripts/fixup_bigquery_storage_v1_keywords.py"],

google/cloud/__init__.py

@@ -0,0 +1,37 @@
+# Copyright 2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is 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.
+
+import os
+import subprocess
+import sys
+
+
+def test_namespace_package_compat(tmp_path):
+    # The ``google`` namespace package should not be masked
+    # by the presence of ``google-cloud-bigquery-storage``.
+    google = tmp_path / "google"
+    google.mkdir()
+    google.joinpath("othermod.py").write_text("")
+    env = dict(os.environ, PYTHONPATH=str(tmp_path))
+    cmd = [sys.executable, "-m", "google.othermod"]
+    subprocess.check_call(cmd, env=env, shell=True)
+
+    # The ``google.cloud`` namespace package should not be masked
+    # by the presence of ``google-cloud-bigquery-storage``.
+    google_cloud = tmp_path / "google" / "cloud"
+    google_cloud.mkdir()
+    google_cloud.joinpath("othermod.py").write_text("")
+    env = dict(os.environ, PYTHONPATH=str(tmp_path))
+    cmd = [sys.executable, "-m", "google.cloud.othermod"]
+    subprocess.check_call(cmd, env=env, shell=True)

setup.py

@@ -20,7 +20,11 @@
 import pandas
 import pandas.testing
 import pytest
-import pkg_resources
+
+try:
+    import importlib.metadata as metadata
+except ImportError:
+    import importlib_metadata as metadata
 
 import google.api_core.exceptions
 from google.cloud.bigquery_storage import types
@@ -30,9 +34,9 @@
 pyarrow = pytest.importorskip("pyarrow")
 
 if pandas is not None:  # pragma: NO COVER
-    PANDAS_INSTALLED_VERSION = pkg_resources.get_distribution("pandas").parsed_version
-else:  # pragma: NO COVER
-    PANDAS_INSTALLED_VERSION = pkg_resources.parse_version("0.0.0")
+    PANDAS_INSTALLED_VERSION = metadata.version("pandas")
+else:
+    PANDAS_INSTALLED_VERSION = "0.0.0"
 
 
 # This dictionary is duplicated in bigquery/google/cloud/bigquery/_pandas_helpers.py
@@ -178,9 +182,7 @@ def test_to_arrow_w_scalars_arrow(class_under_test, mock_gapic_client):
     assert actual_table == expected_table
 
 
-@pytest.mark.skipif(
-    PANDAS_INSTALLED_VERSION >= pkg_resources.parse_version("2.0.0"), reason=""
-)
+@pytest.mark.skipif(PANDAS_INSTALLED_VERSION[0:2] not in ["0.", "1."], reason="")
 def test_to_dataframe_w_scalars_arrow(class_under_test, mock_gapic_client):
     arrow_schema = _bq_to_arrow_schema(SCALAR_COLUMNS)
     arrow_batches = _bq_to_arrow_batches(SCALAR_BLOCKS, arrow_schema)
@@ -248,9 +250,7 @@ def test_to_dataframe_w_dtypes_arrow(class_under_test, mock_gapic_client):
     )
 
 
-@pytest.mark.skipif(
-    PANDAS_INSTALLED_VERSION >= pkg_resources.parse_version("2.0.0"), reason=""
-)
+@pytest.mark.skipif(PANDAS_INSTALLED_VERSION[0:2] not in ["0.", "1."], reason="")
 def test_to_dataframe_empty_w_scalars_arrow(class_under_test, mock_gapic_client):
     arrow_schema = _bq_to_arrow_schema(SCALAR_COLUMNS)
     read_session = _generate_arrow_read_session(arrow_schema)