chore: adds Python 3.7/3.8 EOL pending deprecation warning (#2007)

* adds pending deprecation warning

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* revise code to put version function in version helpers

* Update noxfile.py

* Update google/cloud/bigquery/__init__.py

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Lingqing Gan <[email protected]>

Author: 3 people

google/cloud/bigquery/__init__.py

@@ -115,12 +115,25 @@
 from google.cloud.bigquery.table import TimePartitioningType
 from google.cloud.bigquery.table import TimePartitioning
 from google.cloud.bigquery.encryption_configuration import EncryptionConfiguration
+from google.cloud.bigquery import _versions_helpers
 
 try:
     import bigquery_magics  # type: ignore
 except ImportError:
     bigquery_magics = None
 
+sys_major, sys_minor, sys_micro = _versions_helpers.extract_runtime_version()
+
+if sys_major == 3 and sys_minor in (7, 8):
+    warnings.warn(
+        "The python-bigquery library will stop supporting Python 3.7 "
+        "and Python 3.8 in a future major release expected in Q4 2024. "
+        f"Your Python version is {sys_major}.{sys_minor}.{sys_micro}. We "
+        "recommend that you update soon to ensure ongoing support. For "
+        "more details, see: [Google Cloud Client Libraries Supported Python Versions policy](https://cloud.google.com/python/docs/supported-python-versions)",
+        PendingDeprecationWarning,
+    )
+
 __all__ = [
     "__version__",
     "Client",

google/cloud/bigquery/_versions_helpers.py

@@ -14,6 +14,7 @@
 
 """Shared helper functions for verifying versions of installed modules."""
 
+import sys
 from typing import Any
 
 import packaging.version
@@ -248,3 +249,16 @@ def try_import(self, raise_if_error: bool = False) -> Any:
     and PYARROW_VERSIONS.try_import() is not None
     and PYARROW_VERSIONS.installed_version >= _MIN_PYARROW_VERSION_RANGE
 )
+
+
+def extract_runtime_version():
+    # Retrieve the version information
+    version_info = sys.version_info
+
+    # Extract the major, minor, and micro components
+    major = version_info.major
+    minor = version_info.minor
+    micro = version_info.micro
+
+    # Display the version number in a clear format
+    return major, minor, micro

noxfile.py

@@ -116,6 +116,7 @@ def default(session, install_extras=True):
     session.run(
         "py.test",
         "--quiet",
+        "-W default::PendingDeprecationWarning",
         "--cov=google/cloud/bigquery",
         "--cov=tests/unit",
         "--cov-append",
@@ -231,6 +232,7 @@ def system(session):
     session.run(
         "py.test",
         "--quiet",
+        "-W default::PendingDeprecationWarning",
         os.path.join("tests", "system"),
         *session.posargs,
     )
@@ -299,6 +301,7 @@ def snippets(session):
     session.run(
         "py.test",
         "samples",
+        "-W default::PendingDeprecationWarning",
         "--ignore=samples/desktopapp",
         "--ignore=samples/magics",
         "--ignore=samples/geography",
@@ -401,9 +404,23 @@ def prerelease_deps(session):
     session.run("python", "-m", "pip", "freeze")
 
     # Run all tests, except a few samples tests which require extra dependencies.
-    session.run("py.test", "tests/unit")
-    session.run("py.test", "tests/system")
-    session.run("py.test", "samples/tests")
+    session.run(
+        "py.test",
+        "tests/unit",
+        "-W default::PendingDeprecationWarning",
+    )
+
+    session.run(
+        "py.test",
+        "tests/system",
+        "-W default::PendingDeprecationWarning",
+    )
+
+    session.run(
+        "py.test",
+        "samples/tests",
+        "-W default::PendingDeprecationWarning",
+    )
 
 
 @nox.session(python=DEFAULT_PYTHON_VERSION)