fix: drop packaging and pkg_resources

gapic/templates/%namespace/%name_%version/%sub/__init__.py.j2

@@ -5,10 +5,46 @@
 {% set package_path = api.naming.module_namespace|join('.') + "." + api.naming.versioned_module_name %}
 from {{package_path}} import gapic_version as package_version
 
+import google.api_core as api_core
+import sys
+
 __version__ = package_version.__version__
 
+if sys.version_info >= (3, 8):  # pragma: NO COVER
+    from importlib import metadata
+else:  # pragma: NO COVER
+    # TODO(https://github.com/googleapis/python-api-core/issues/835): Remove
+    # this code path once we drop support for Python 3.7
+    import importlib_metadata as metadata
 
-import google.api_core as api_core
+{#  Import subpackages. -#}
+{% for subpackage, _ in api.subpackages|dictsort %}
+from . import {{ subpackage }}
+{% endfor %}
+
+{#  Import services for this package. -#}
+{% for service in api.services.values()|sort(attribute='name')
+        if service.meta.address.subpackage == api.subpackage_view %}
+from .services.{{ service.name|snake_case }} import {{ service.client_name }}
+{% if 'grpc' in opts.transport %}
+from .services.{{ service.name|snake_case }} import {{ service.async_client_name }}
+{% endif %}
+{% endfor %}
+
+{#  Import messages and enums from each proto.
+    It is safe to import all of the messages into the same namespace here,
+    because protocol buffers itself enforces selector uniqueness within
+    a proto package.
+-#}
+{% for proto in api.protos.values()|sort(attribute='name')
+        if proto.meta.address.subpackage == api.subpackage_view %}
+{% for message in proto.messages.values()|sort(attribute='name') %}
+from .types.{{ proto.module_name }} import {{ message.name }}
+{% endfor %}
+{% for enum in proto.enums.values()|sort(attribute='name') %}
+from .types.{{ proto.module_name }} import {{ enum.name }}
+{% endfor %}
+{% endfor %}
 
 if hasattr(api_core, "check_python_version") and hasattr(api_core, "check_dependency_versions"):   # pragma: NO COVER
     {# TODO(api_core): remove `type:ignore` below when minimum version of api_core makes the else clause unnecessary. #}
@@ -45,27 +81,35 @@ else:   # pragma: NO COVER
                           f"then update {_package_label}.",
                           FutureWarning)
 
-        from packaging.version import parse as parse_version
-
-        if sys.version_info < (3, 8):
-            import pkg_resources
-
-            def _get_version(dependency_name):
-              try:
-                version_string = pkg_resources.get_distribution(dependency_name).version
-                return (parse_version(version_string), version_string)
-              except pkg_resources.DistributionNotFound:
-                return (None, "--")
-        else:
-            from importlib import metadata
-
-            def _get_version(dependency_name):
+        def parse_version_to_tuple(version_string: str):
+            """Safely converts a semantic version string to a comparable tuple of integers.
+            Example: "4.25.8" -> (4, 25, 8)
+            Ignores non-numeric parts and handles common version formats.
+            Args:
+                version_string: Version string in the format "x.y.z" or "x.y.z<suffix>"
+            Returns:
+                Tuple of integers for the parsed version string.
+            """
+            parts = []
+            for part in version_string.split("."):
                 try:
-                    version_string = metadata.version("requests")
-                    parsed_version = parse_version(version_string)
-                    return (parsed_version.release, version_string)
-                except metadata.PackageNotFoundError:
-                    return (None, "--")
+                    parts.append(int(part))
+                except ValueError:
+                    # If it's a non-numeric part (e.g., '1.0.0b1' -> 'b1'), stop here.
+                    # This is a simplification compared to 'packaging.parse_version', but sufficient
+                    # for comparing strictly numeric semantic versions.
+                    break
+            return tuple(parts)
+
+        def _get_version(dependency_name):
+            try:
+                version_string: str = metadata.version(dependency_name)
+                parsed_version = parse_version_to_tuple(version_string)
+                return (parsed_version, version_string)
+            except Exception:
+                # Catch exceptions from metadata.version() (e.g., PackageNotFoundError)
+                # or errors during parse_version_to_tuple
+                return (None, "--")
 
         _dependency_package = "google.protobuf"
         _next_supported_version = "4.25.8"
@@ -93,35 +137,6 @@ else:   # pragma: NO COVER
                           "using a supported version of Python; see " +
                           "https://devguide.python.org/versions/")
 
-{#  Import subpackages. -#}
-{% for subpackage, _ in api.subpackages|dictsort %}
-from . import {{ subpackage }}
-{% endfor %}
-
-{#  Import services for this package. -#}
-{% for service in api.services.values()|sort(attribute='name')
-        if service.meta.address.subpackage == api.subpackage_view %}
-from .services.{{ service.name|snake_case }} import {{ service.client_name }}
-{% if 'grpc' in opts.transport %}
-from .services.{{ service.name|snake_case }} import {{ service.async_client_name }}
-{% endif %}
-{% endfor %}
-
-{#  Import messages and enums from each proto.
-    It is safe to import all of the messages into the same namespace here,
-    because protocol buffers itself enforces selector uniqueness within
-    a proto package.
--#}
-{% for proto in api.protos.values()|sort(attribute='name')
-        if proto.meta.address.subpackage == api.subpackage_view %}
-{% for message in proto.messages.values()|sort(attribute='name') %}
-from .types.{{ proto.module_name }} import {{ message.name }}
-{% endfor %}
-{% for enum in proto.enums.values()|sort(attribute='name') %}
-from .types.{{ proto.module_name }} import {{ enum.name }}
-{% endfor %}
-{% endfor %}
-
 {#  Define __all__.
     This requires the full set of imported names, so we iterate over
     them again.

gapic/templates/setup.py.j2

@@ -39,7 +39,6 @@ dependencies = [
     "google-auth >= 2.14.1, <3.0.0,!=2.24.0,!=2.25.0",
     "grpcio >= 1.33.2, < 2.0.0",
     "grpcio >= 1.75.1, < 2.0.0; python_version >= '3.14'",
-    "packaging", # TODO: Remove once we require versions of api core that include this
     "proto-plus >= 1.22.3, <2.0.0",
     "proto-plus >= 1.25.0, <2.0.0; python_version >= '3.13'",
     {# Explicitly exclude protobuf versions mentioned in https://cloud.google.com/support/bulletins#GCP-2022-019 #}

noxfile.py

@@ -64,8 +64,6 @@ def unit(session):
         "pyfakefs",
         "grpcio-status",
         "proto-plus",
-        "setuptools",  # TODO: Remove when not needed in __init__.py.j2
-        "packaging",  # TODO: Remove when not needed in __init__.py.j2
     )
     session.install("-e", ".")
     session.run(
@@ -501,8 +499,6 @@ def run_showcase_unit_tests(session, fail_under=100, rest_async_io_enabled=False
         "pytest-xdist",
         "asyncmock; python_version < '3.8'",
         "pytest-asyncio",
-        "setuptools",  # TODO: Remove when not needed in __init__.py.j2
-        "packaging",  # TODO: Remove when not needed in __init__.py.j2
     )
     # Run the tests.
     # NOTE: async rest is not supported against the minimum supported version of google-api-core.
@@ -617,8 +613,6 @@ def showcase_mypy(
         "types-protobuf",
         "types-requests",
         "types-dataclasses",
-        "setuptools",  # TODO: Remove when not needed in __init__.py.j2
-        "packaging",  # TODO: Remove when not needed in __init__.py.j2
     )
 
     with showcase_library(session, templates=templates, other_opts=other_opts) as lib:
@@ -749,8 +743,6 @@ def mypy(session):
         "types-PyYAML",
         "types-dataclasses",
         "click==8.1.3",
-        "setuptools",  # TODO: Remove when not needed in __init__.py.j2
-        "packaging",  # TODO: Remove when not needed in __init__.py.j2
     )
     session.install(".")
     session.run("mypy", "-p", "gapic")

tests/integration/goldens/asset/google/cloud/asset_v1/__init__.py

@@ -15,86 +15,17 @@
 #
 from google.cloud.asset_v1 import gapic_version as package_version
 
-__version__ = package_version.__version__
-
-
 import google.api_core as api_core
+import sys
 
-if hasattr(api_core, "check_python_version") and hasattr(api_core, "check_dependency_versions"):   # pragma: NO COVER
-    api_core.check_python_version("google.cloud.asset_v1") # type: ignore
-    api_core.check_dependency_versions("google.cloud.asset_v1") # type: ignore
-else:   # pragma: NO COVER
-    # An older version of api_core is installed which does not define the
-    # functions above. We do equivalent checks manually.
-    try:
-        import warnings
-        import sys
-
-        _py_version_str = sys.version.split()[0]
-        _package_label = "google.cloud.asset_v1"
-        if sys.version_info < (3, 9):
-            warnings.warn("You are using a non-supported Python version " +
-                          f"({_py_version_str}).  Google will not post any further " +
-                          f"updates to {_package_label} supporting this Python version. " +
-                          "Please upgrade to the latest Python version, or at " +
-                          f"least to Python 3.9, and then update {_package_label}.",
-                          FutureWarning)
-        if sys.version_info[:2] == (3, 9):
-            warnings.warn(f"You are using a Python version ({_py_version_str}) " +
-                          f"which Google will stop supporting in {_package_label} in " +
-                          "January 2026. Please " +
-                          "upgrade to the latest Python version, or at " +
-                          "least to Python 3.10, before then, and " +
-                          f"then update {_package_label}.",
-                          FutureWarning)
-
-        from packaging.version import parse as parse_version
-
-        if sys.version_info < (3, 8):
-            import pkg_resources
-
-            def _get_version(dependency_name):
-              try:
-                version_string = pkg_resources.get_distribution(dependency_name).version
-                return (parse_version(version_string), version_string)
-              except pkg_resources.DistributionNotFound:
-                return (None, "--")
-        else:
-            from importlib import metadata
-
-            def _get_version(dependency_name):
-                try:
-                    version_string = metadata.version("requests")
-                    parsed_version = parse_version(version_string)
-                    return (parsed_version.release, version_string)
-                except metadata.PackageNotFoundError:
-                    return (None, "--")
+__version__ = package_version.__version__
 
-        _dependency_package = "google.protobuf"
-        _next_supported_version = "4.25.8"
-        _next_supported_version_tuple = (4, 25, 8)
-        _recommendation = " (we recommend 6.x)"
-        (_version_used, _version_used_string) = _get_version(_dependency_package)
-        if _version_used and _version_used < _next_supported_version_tuple:
-            warnings.warn(f"Package {_package_label} depends on " +
-                          f"{_dependency_package}, currently installed at version " +
-                          f"{_version_used_string}. Future updates to " +
-                          f"{_package_label} will require {_dependency_package} at " +
-                          f"version {_next_supported_version} or higher{_recommendation}." +
-                          " Please ensure " +
-                          "that either (a) your Python environment doesn't pin the " +
-                          f"version of {_dependency_package}, so that updates to " +
-                          f"{_package_label} can require the higher version, or " +
-                          "(b) you manually update your Python environment to use at " +
-                          f"least version {_next_supported_version} of " +
-                          f"{_dependency_package}.",
-                          FutureWarning)
-    except Exception:
-            warnings.warn("Could not determine the version of Python " +
-                          "currently being used. To continue receiving " +
-                          "updates for {_package_label}, ensure you are " +
-                          "using a supported version of Python; see " +
-                          "https://devguide.python.org/versions/")
+if sys.version_info >= (3, 8):  # pragma: NO COVER
+    from importlib import metadata
+else:  # pragma: NO COVER
+    # TODO(https://github.com/googleapis/python-api-core/issues/835): Remove
+    # this code path once we drop support for Python 3.7
+    import importlib_metadata as metadata
 
 
 from .services.asset_service import AssetServiceClient
@@ -178,6 +109,90 @@ def _get_version(dependency_name):
 from .types.assets import TimeWindow
 from .types.assets import VersionedResource
 
+if hasattr(api_core, "check_python_version") and hasattr(api_core, "check_dependency_versions"):   # pragma: NO COVER
+    api_core.check_python_version("google.cloud.asset_v1") # type: ignore
+    api_core.check_dependency_versions("google.cloud.asset_v1") # type: ignore
+else:   # pragma: NO COVER
+    # An older version of api_core is installed which does not define the
+    # functions above. We do equivalent checks manually.
+    try:
+        import warnings
+        import sys
+
+        _py_version_str = sys.version.split()[0]
+        _package_label = "google.cloud.asset_v1"
+        if sys.version_info < (3, 9):
+            warnings.warn("You are using a non-supported Python version " +
+                          f"({_py_version_str}).  Google will not post any further " +
+                          f"updates to {_package_label} supporting this Python version. " +
+                          "Please upgrade to the latest Python version, or at " +
+                          f"least to Python 3.9, and then update {_package_label}.",
+                          FutureWarning)
+        if sys.version_info[:2] == (3, 9):
+            warnings.warn(f"You are using a Python version ({_py_version_str}) " +
+                          f"which Google will stop supporting in {_package_label} in " +
+                          "January 2026. Please " +
+                          "upgrade to the latest Python version, or at " +
+                          "least to Python 3.10, before then, and " +
+                          f"then update {_package_label}.",
+                          FutureWarning)
+
+        def parse_version_to_tuple(version_string: str):
+            """Safely converts a semantic version string to a comparable tuple of integers.
+            Example: "4.25.8" -> (4, 25, 8)
+            Ignores non-numeric parts and handles common version formats.
+            Args:
+                version_string: Version string in the format "x.y.z" or "x.y.z<suffix>"
+            Returns:
+                Tuple of integers for the parsed version string.
+            """
+            parts = []
+            for part in version_string.split("."):
+                try:
+                    parts.append(int(part))
+                except ValueError:
+                    # If it's a non-numeric part (e.g., '1.0.0b1' -> 'b1'), stop here.
+                    # This is a simplification compared to 'packaging.parse_version', but sufficient
+                    # for comparing strictly numeric semantic versions.
+                    break
+            return tuple(parts)
+
+        def _get_version(dependency_name):
+            try:
+                version_string: str = metadata.version(dependency_name)
+                parsed_version = parse_version_to_tuple(version_string)
+                return (parsed_version, version_string)
+            except Exception:
+                # Catch exceptions from metadata.version() (e.g., PackageNotFoundError)
+                # or errors during parse_version_to_tuple
+                return (None, "--")
+
+        _dependency_package = "google.protobuf"
+        _next_supported_version = "4.25.8"
+        _next_supported_version_tuple = (4, 25, 8)
+        _recommendation = " (we recommend 6.x)"
+        (_version_used, _version_used_string) = _get_version(_dependency_package)
+        if _version_used and _version_used < _next_supported_version_tuple:
+            warnings.warn(f"Package {_package_label} depends on " +
+                          f"{_dependency_package}, currently installed at version " +
+                          f"{_version_used_string}. Future updates to " +
+                          f"{_package_label} will require {_dependency_package} at " +
+                          f"version {_next_supported_version} or higher{_recommendation}." +
+                          " Please ensure " +
+                          "that either (a) your Python environment doesn't pin the " +
+                          f"version of {_dependency_package}, so that updates to " +
+                          f"{_package_label} can require the higher version, or " +
+                          "(b) you manually update your Python environment to use at " +
+                          f"least version {_next_supported_version} of " +
+                          f"{_dependency_package}.",
+                          FutureWarning)
+    except Exception:
+            warnings.warn("Could not determine the version of Python " +
+                          "currently being used. To continue receiving " +
+                          "updates for {_package_label}, ensure you are " +
+                          "using a supported version of Python; see " +
+                          "https://devguide.python.org/versions/")
+
 __all__ = (
     'AssetServiceAsyncClient',
 'AnalyzeIamPolicyLongrunningMetadata',

tests/integration/goldens/asset/setup.py

@@ -45,7 +45,6 @@
     "google-auth >= 2.14.1, <3.0.0,!=2.24.0,!=2.25.0",
     "grpcio >= 1.33.2, < 2.0.0",
     "grpcio >= 1.75.1, < 2.0.0; python_version >= '3.14'",
-    "packaging", # TODO: Remove once we require versions of api core that include this
     "proto-plus >= 1.22.3, <2.0.0",
     "proto-plus >= 1.25.0, <2.0.0; python_version >= '3.13'",
     "protobuf>=3.20.2,<7.0.0,!=4.21.0,!=4.21.1,!=4.21.2,!=4.21.3,!=4.21.4,!=4.21.5",