Python: Migrate to use "implicit namespace packages" (PEP 420)

... instead of "declared namespaces" for the `crate` namespace package,
see PEP 420 [1], and setuptools docs [2].

> Historically, there were two methods to create namespace packages. One
> is the `pkg_resources` style supported by `setuptools` and the other
> one being `pkgutils` style offered by `pkgutils` module in Python.
> Both are now considered _deprecated_.
>
> -- Legacy Namespace Packages [3]

[1] https://peps.python.org/pep-0420/
[2] https://setuptools.pypa.io/en/latest/references/keywords.html#keyword-namespace-packages
[3] https://setuptools.pypa.io/en/latest/userguide/package_discovery.html#legacy-namespace-packages

CHANGES.txt

@@ -17,9 +17,12 @@ Unreleased
 - Error handling: At two spots in cursor / value converter handling, where
   ``assert`` statements have been used, ``ValueError`` exceptions are raised
   now.
+- Python: Migrated to use "implicit namespace packages" instead of "declared
+  namespaces" for the ``crate`` namespace package, see `PEP 420`_.
 
 
 .. _Migrate from crate.client to sqlalchemy-cratedb: https://cratedb.com/docs/sqlalchemy-cratedb/migrate-from-crate-client.html
+.. _PEP 420: https://peps.python.org/pep-0420/
 .. _sqlalchemy-cratedb: https://pypi.org/project/sqlalchemy-cratedb/
 
 

setup.py

@@ -22,7 +22,7 @@
 import os
 import re
 
-from setuptools import find_packages, setup
+from setuptools import find_namespace_packages, setup
 
 
 def read(path):
@@ -45,15 +45,14 @@ def read(path):
     url="https://github.com/crate/crate-python",
     author="Crate.io",
     author_email="[email protected]",
-    package_dir={"": "src"},
     description="CrateDB Python Client",
     long_description=long_description,
     long_description_content_type="text/x-rst",
     platforms=["any"],
     license="Apache License 2.0",
     keywords="cratedb db api dbapi database sql http rdbms olap",
-    packages=find_packages("src"),
-    namespace_packages=["crate"],
+    packages=find_namespace_packages("src"),
+    package_dir={"": "src"},
     install_requires=[
         "urllib3<2.3",
         "verlib2==0.2.0",

src/crate/__init__.py

@@ -1,30 +0,0 @@
-# -*- coding: utf-8; -*-
-#
-# Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
-# license agreements.  See the NOTICE file distributed with this work for
-# additional information regarding copyright ownership.  Crate licenses
-# this file to you 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.
-#
-# However, if you have executed another commercial license agreement
-# with Crate these terms will supersede the license and you may use the
-# software solely pursuant to the terms of the relevant commercial agreement.
-
-# this is a namespace package
-try:
-    import pkg_resources
-
-    pkg_resources.declare_namespace(__name__)
-except ImportError:
-    import pkgutil
-
-    __path__ = pkgutil.extend_path(__path__, __name__)

src/crate/testing/__init__.py

@@ -1 +0,0 @@
-# package