feat: implement native PEP 0810 lazy loading

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

@@ -12,6 +12,28 @@ __version__ = package_version.__version__
 
 from importlib import metadata
 
+# PEP 0810: Explicit Lazy Imports
+# Python 3.15+ natively intercepts and defers these imports.
+# Developers can disable this behavior and force eager imports.
+# For more information, see:
+# https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
+# Older Python versions safely ignore this variable.
+__lazy_modules__ = {
+    {% filter sort_lines -%}
+    {% for subpackage, _ in api.subpackages|dictsort -%}
+    f"{__name__}.{{ subpackage }}",
+    {% endfor -%}
+    {% for service in api.services.values()
+            if service.meta.address.subpackage == api.subpackage_view -%}
+    f"{__name__}.services.{{ service.name|snake_case }}",
+    {% endfor -%}
+    {% for proto in api.protos.values()
+            if proto.meta.address.subpackage == api.subpackage_view -%}
+    f"{__name__}.types.{{ proto.module_name }}",
+    {% endfor -%}
+    {% endfilter %}
+}
+
 {#  Import subpackages. -#}
 {% for subpackage, _ in api.subpackages|dictsort %}
 from . import {{ subpackage }}

packages/gapic-generator/tests/integration/goldens/asset/google/cloud/asset_v1/__init__.py

@@ -22,6 +22,19 @@
 
 from importlib import metadata
 
+# PEP 0810: Explicit Lazy Imports
+# Python 3.15+ natively intercepts and defers these imports.
+# Developers can disable this behavior and force eager imports.
+# For more information, see:
+# https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
+# Older Python versions safely ignore this variable.
+__lazy_modules__ = {
+f"{__name__}.services.asset_service",
+f"{__name__}.types.asset_enrichment_resourceowners",
+f"{__name__}.types.asset_service",
+f"{__name__}.types.assets",
+}
+
 
 from .services.asset_service import AssetServiceClient
 from .services.asset_service import AssetServiceAsyncClient

packages/gapic-generator/tests/integration/goldens/credentials/google/iam/credentials_v1/__init__.py

@@ -22,6 +22,18 @@
 
 from importlib import metadata
 
+# PEP 0810: Explicit Lazy Imports
+# Python 3.15+ natively intercepts and defers these imports.
+# Developers can disable this behavior and force eager imports.
+# For more information, see:
+# https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
+# Older Python versions safely ignore this variable.
+__lazy_modules__ = {
+f"{__name__}.services.iam_credentials",
+f"{__name__}.types.common",
+f"{__name__}.types.iamcredentials",
+}
+
 
 from .services.iam_credentials import IAMCredentialsClient
 from .services.iam_credentials import IAMCredentialsAsyncClient

packages/gapic-generator/tests/integration/goldens/eventarc/google/cloud/eventarc_v1/__init__.py

@@ -22,6 +22,28 @@
 
 from importlib import metadata
 
+# PEP 0810: Explicit Lazy Imports
+# Python 3.15+ natively intercepts and defers these imports.
+# Developers can disable this behavior and force eager imports.
+# For more information, see:
+# https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
+# Older Python versions safely ignore this variable.
+__lazy_modules__ = {
+f"{__name__}.services.eventarc",
+f"{__name__}.types.channel",
+f"{__name__}.types.channel_connection",
+f"{__name__}.types.discovery",
+f"{__name__}.types.enrollment",
+f"{__name__}.types.eventarc",
+f"{__name__}.types.google_api_source",
+f"{__name__}.types.google_channel_config",
+f"{__name__}.types.logging_config",
+f"{__name__}.types.message_bus",
+f"{__name__}.types.network_config",
+f"{__name__}.types.pipeline",
+f"{__name__}.types.trigger",
+}
+
 
 from .services.eventarc import EventarcClient
 from .services.eventarc import EventarcAsyncClient

packages/gapic-generator/tests/integration/goldens/logging/google/cloud/logging_v2/__init__.py

@@ -22,6 +22,22 @@
 
 from importlib import metadata
 
+# PEP 0810: Explicit Lazy Imports
+# Python 3.15+ natively intercepts and defers these imports.
+# Developers can disable this behavior and force eager imports.
+# For more information, see:
+# https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
+# Older Python versions safely ignore this variable.
+__lazy_modules__ = {
+f"{__name__}.services.config_service_v2",
+f"{__name__}.services.logging_service_v2",
+f"{__name__}.services.metrics_service_v2",
+f"{__name__}.types.log_entry",
+f"{__name__}.types.logging",
+f"{__name__}.types.logging_config",
+f"{__name__}.types.logging_metrics",
+}
+
 
 from .services.config_service_v2 import ConfigServiceV2Client
 from .services.config_service_v2 import ConfigServiceV2AsyncClient

packages/gapic-generator/tests/integration/goldens/logging_internal/google/cloud/logging_v2/__init__.py

@@ -22,6 +22,22 @@
 
 from importlib import metadata
 
+# PEP 0810: Explicit Lazy Imports
+# Python 3.15+ natively intercepts and defers these imports.
+# Developers can disable this behavior and force eager imports.
+# For more information, see:
+# https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
+# Older Python versions safely ignore this variable.
+__lazy_modules__ = {
+f"{__name__}.services.config_service_v2",
+f"{__name__}.services.logging_service_v2",
+f"{__name__}.services.metrics_service_v2",
+f"{__name__}.types.log_entry",
+f"{__name__}.types.logging",
+f"{__name__}.types.logging_config",
+f"{__name__}.types.logging_metrics",
+}
+
 
 from .services.config_service_v2 import BaseConfigServiceV2Client
 from .services.config_service_v2 import BaseConfigServiceV2AsyncClient

packages/gapic-generator/tests/integration/goldens/redis/google/cloud/redis_v1/__init__.py

@@ -22,6 +22,17 @@
 
 from importlib import metadata
 
+# PEP 0810: Explicit Lazy Imports
+# Python 3.15+ natively intercepts and defers these imports.
+# Developers can disable this behavior and force eager imports.
+# For more information, see:
+# https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
+# Older Python versions safely ignore this variable.
+__lazy_modules__ = {
+f"{__name__}.services.cloud_redis",
+f"{__name__}.types.cloud_redis",
+}
+
 
 from .services.cloud_redis import CloudRedisClient
 from .services.cloud_redis import CloudRedisAsyncClient

packages/gapic-generator/tests/integration/goldens/redis_selective/google/cloud/redis_v1/__init__.py

@@ -22,6 +22,17 @@
 
 from importlib import metadata
 
+# PEP 0810: Explicit Lazy Imports
+# Python 3.15+ natively intercepts and defers these imports.
+# Developers can disable this behavior and force eager imports.
+# For more information, see:
+# https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
+# Older Python versions safely ignore this variable.
+__lazy_modules__ = {
+f"{__name__}.services.cloud_redis",
+f"{__name__}.types.cloud_redis",
+}
+
 
 from .services.cloud_redis import CloudRedisClient
 from .services.cloud_redis import CloudRedisAsyncClient

packages/gapic-generator/tests/integration/goldens/storagebatchoperations/google/cloud/storagebatchoperations_v1/__init__.py

@@ -22,6 +22,18 @@
 
 from importlib import metadata
 
+# PEP 0810: Explicit Lazy Imports
+# Python 3.15+ natively intercepts and defers these imports.
+# Developers can disable this behavior and force eager imports.
+# For more information, see:
+# https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
+# Older Python versions safely ignore this variable.
+__lazy_modules__ = {
+f"{__name__}.services.storage_batch_operations",
+f"{__name__}.types.storage_batch_operations",
+f"{__name__}.types.storage_batch_operations_types",
+}
+
 
 from .services.storage_batch_operations import StorageBatchOperationsClient
 from .services.storage_batch_operations import StorageBatchOperationsAsyncClient