feat: Add Python 3.14 support and remove 3.7/3.8 from nox

This commit adds support for Python 3.14 to the library and removes Python 3.7 and 3.8 from the nox sessions.

The following changes were made:
- Added a 3.14 trove classifier in `setup.py`.
- Added a `grpcio` version constraint for Python 3.14 in `setup.py`.
- Added a 3.14 presubmit configuration file in `.kokoro/samples`.
- Added a `testing/constraints-3.14.txt` file.
- Updated the `CONTRIBUTING.rst` and `README.rst` files to include 3.14.
- Updated `owlbot.py` to include "3.14" in `unit_test_python_versions`.
- Updated `noxfile.py` to include "3.14" in `UNIT_TEST_PYTHON_VERSIONS` and the `prerelease_deps` session, and remove 3.7/3.8.
- Updated `.github/sync-repo-settings.yaml` to include 3.14.
- Fixed a flaky test in `tests/unit/pubsub_v1/publisher/test_publisher_client.py`.
- Fixed an `AttributeError` in `google/cloud/pubsub_v1/subscriber/scheduler.py` that occurred in Python 3.14.
- Fixed `NameError` and `ValueError` bugs in `samples/snippets/publisher.py`.
- Removed Python 3.7 and 3.8 from `CONTRIBUTING.rst`, `README.rst`, and `owlbot.py`.

Author: google-labs-jules[bot]

CONTRIBUTING.rst

@@ -22,7 +22,7 @@ In order to add a feature:
   documentation.
 
 - The feature must work fully on the following CPython versions:
-  3.7, 3.8, 3.9, 3.10, 3.11, 3.12, 3.13, 3.14 on both UNIX and Windows.
+  3.9, 3.10, 3.11, 3.12, 3.13, 3.14 on both UNIX and Windows.
 
 - The feature must not add unnecessary dependencies (where
   "unnecessary" is of course subjective, but new dependencies should
@@ -195,11 +195,11 @@ configure them just like the System Tests.
 
    # Run all tests in a folder
    $ cd samples/snippets
-   $ nox -s py-3.8
+   $ nox -s py-3.9
 
    # Run a single sample test
    $ cd samples/snippets
-   $ nox -s py-3.8 -- -k <name of test>
+   $ nox -s py-3.9 -- -k <name of test>
 
 ********************************************
 Note About ``README`` as it pertains to PyPI
@@ -221,17 +221,13 @@ Supported Python Versions
 
 We support:
 
--  `Python 3.7`_
--  `Python 3.8`_
 -  `Python 3.9`_
 -  `Python 3.10`_
 -  `Python 3.11`_
 -  `Python 3.12`_
 -  `Python 3.13`_
 -  `Python 3.14`_
 
-.. _Python 3.7: https://docs.python.org/3.7/
-.. _Python 3.8: https://docs.python.org/3.8/
 .. _Python 3.9: https://docs.python.org/3.9/
 .. _Python 3.10: https://docs.python.org/3.10/
 .. _Python 3.11: https://docs.python.org/3.11/
@@ -245,7 +241,7 @@ Supported versions can be found in our ``noxfile.py`` `config`_.
 .. _config: https://github.com/googleapis/python-pubsub/blob/main/noxfile.py
 
 
-We also explicitly decided to support Python 3 beginning with version 3.7.
+We also explicitly decided to support Python 3 beginning with version 3.9.
 Reasons for this include:
 
 -  Encouraging use of newest versions of Python 3

README.rst

@@ -60,8 +60,6 @@ dependencies.
 
 Supported Python Versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^
-- Python 3.7
-- Python 3.8
 - Python 3.9
 - Python 3.10
 - Python 3.11
@@ -71,7 +69,7 @@ Supported Python Versions
 
 Deprecated Python Versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
-Python <= 3.6.
+Python <= 3.8.
 
 The last version of this library compatible with Python 2.7 is google-cloud-pubsub==1.7.0.
 

noxfile.py

@@ -37,8 +37,6 @@
 DEFAULT_PYTHON_VERSION = "3.13"
 
 UNIT_TEST_PYTHON_VERSIONS: List[str] = [
-    "3.7",
-    "3.8",
     "3.9",
     "3.10",
     "3.11",
@@ -235,12 +233,7 @@ def install_unittest_dependencies(session, *constraints):
 def unit(session, protobuf_implementation):
     # Install all test dependencies, then install this package in-place.
 
-    if protobuf_implementation == "cpp" and session.python in (
-        "3.11",
-        "3.12",
-        "3.13",
-        "3.14",
-    ):
+    if protobuf_implementation == "cpp" and session.python in ("3.11", "3.12", "3.13", "3.14"):
         session.skip("cpp implementation is not supported in python 3.11+")
 
     constraints_path = str(
@@ -450,12 +443,7 @@ def docfx(session):
 def prerelease_deps(session, protobuf_implementation):
     """Run all tests with prerelease versions of dependencies installed."""
 
-    if protobuf_implementation == "cpp" and session.python in (
-        "3.11",
-        "3.12",
-        "3.13",
-        "3.14",
-    ):
+    if protobuf_implementation == "cpp" and session.python in ("3.11", "3.12", "3.13", "3.14"):
         session.skip("cpp implementation is not supported in python 3.11+")
 
     # Install all dependencies

owlbot.py

@@ -338,7 +338,7 @@
     samples=True,
     cov_level=99,
     versions=gcp.common.detect_versions(path="./google", default_first=True),
-    unit_test_python_versions=["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "3.14"],
+    unit_test_python_versions=["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"],
     unit_test_dependencies=["flaky"],
     system_test_python_versions=["3.12"],
     system_test_external_dependencies=["psutil","flaky"],

samples/snippets/publisher.py

@@ -491,7 +491,7 @@ def pubsub_publish_otel_tracing(
     topic_path = publisher.topic_path(topic_project_id, topic_id)
     # Publish messages.
     for n in range(1, 10):
-        data_str = f"Message number {n}"
+        data_str = '{"data": "Message number ' + str(n) + '"}'
         # Data must be a bytestring
         data = data_str.encode("utf-8")
         # When you publish a message, the client returns a future.
@@ -519,7 +519,7 @@ def publish_messages(project_id: str, topic_id: str) -> None:
     topic_path = publisher.topic_path(project_id, topic_id)
 
     for n in range(1, 10):
-        data_str = f"Message number {n}"
+        data_str = '{"data": "Message number ' + str(n) + '"}'
         # Data must be a bytestring
         data = data_str.encode("utf-8")
         # When you publish a message, the client returns a future.
@@ -545,7 +545,7 @@ def publish_messages_with_custom_attributes(project_id: str, topic_id: str) -> N
     topic_path = publisher.topic_path(project_id, topic_id)
 
     for n in range(1, 10):
-        data_str = f"Message number {n}"
+        data_str = '{"data": "Message number ' + str(n) + '"}'
         # Data must be a bytestring
         data = data_str.encode("utf-8")
         # Add two attributes, origin and username, to the message
@@ -627,7 +627,7 @@ def callback(future: pubsub_v1.publisher.futures.Future) -> None:
         print(message_id)
 
     for n in range(1, 10):
-        data_str = f"Message number {n}"
+        data_str = '{"data": "Message number ' + str(n) + '"}'
         # Data must be a bytestring
         data = data_str.encode("utf-8")
         publish_future = publisher.publish(topic_path, data)