fix: require python 3.7+ (#468)

* chore(python): drop python 3.6

Source-Link: googleapis/synthtool@4f89b13
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:e7bb19d47c13839fe8c147e50e02e8b6cf5da8edd1af8b82208cd6f66cc2829c

* require python 3.7+ in setup.py

* remove python 3.6 sample configs

* exclude templated README

* 🦉 Updates from OwlBot post-processor

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

* update python_requires in setup.py

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Anthonios Partheniou <partheniou@google.com>

Author: gcf-owl-bot[bot]

.github/.OwlBot.lock.yaml

@@ -13,5 +13,5 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-python:latest
-  digest: sha256:81ed5ecdfc7cac5b699ba4537376f3563f6f04122c4ec9e735d3b3dc1d43dd32
-# created: 2022-05-05T22:08:23.383410683Z
+  digest: sha256:e7bb19d47c13839fe8c147e50e02e8b6cf5da8edd1af8b82208cd6f66cc2829c
+# created: 2022-07-05T18:31:20.838186805Z

.kokoro/continuous/prerelease-deps.cfg

@@ -0,0 +1,7 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+# Only run this nox session.
+env_vars: {
+    key: "NOX_SESSION"
+    value: "prerelease_deps"
+}

.kokoro/presubmit/prerelease-deps.cfg

@@ -0,0 +1,7 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+# Only run this nox session.
+env_vars: {
+    key: "NOX_SESSION"
+    value: "prerelease_deps"
+}

.kokoro/samples/python3.6/common.cfg

@@ -33,7 +33,7 @@ export PYTHONUNBUFFERED=1
 env | grep KOKORO
 
 # Install nox
-python3.6 -m pip install --upgrade --quiet nox
+python3.9 -m pip install --upgrade --quiet nox
 
 # Use secrets acessor service account to get secrets
 if [[ -f "${KOKORO_GFILE_DIR}/secrets_viewer_service_account.json" ]]; then
@@ -76,7 +76,7 @@ for file in samples/**/requirements.txt; do
     echo "------------------------------------------------------------"
 
     # Use nox to execute the tests for the project.
-    python3.6 -m nox -s "$RUN_TESTS_SESSION"
+    python3.9 -m nox -s "$RUN_TESTS_SESSION"
     EXIT=$?
 
     # If this is a periodic build, send the test log to the FlakyBot.

.kokoro/samples/python3.6/continuous.cfg

@@ -22,7 +22,7 @@ In order to add a feature:
   documentation.
 
 - The feature must work fully on the following CPython versions:
-  3.6, 3.7, 3.8, 3.9 and 3.10 on both UNIX and Windows.
+  3.7, 3.8, 3.9 and 3.10 on both UNIX and Windows.
 
 - The feature must not add unnecessary dependencies (where
   "unnecessary" is of course subjective, but new dependencies should
@@ -221,13 +221,11 @@ Supported Python Versions
 
 We support:
 
--  `Python 3.6`_
 -  `Python 3.7`_
 -  `Python 3.8`_
 -  `Python 3.9`_
 -  `Python 3.10`_
 
-.. _Python 3.6: https://docs.python.org/3.6/
 .. _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/
@@ -239,7 +237,7 @@ Supported versions can be found in our ``noxfile.py`` `config`_.
 .. _config: https://github.com/googleapis/python-bigquery-sqlalchemy/blob/main/noxfile.py
 
 
-We also explicitly decided to support Python 3 beginning with version 3.6.
+We also explicitly decided to support Python 3 beginning with version 3.7.
 Reasons for this include:
 
 -  Encouraging use of newest versions of Python 3

.kokoro/samples/python3.6/periodic-head.cfg

@@ -50,11 +50,11 @@ dependencies.
 
 Supported Python Versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^
-Python >= 3.6
+Python >= 3.7
 
 Unsupported Python Versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Python <= 3.5.
+Python <= 3.6.
 
 
 Mac/Linux

.kokoro/samples/python3.6/periodic.cfg

@@ -20,6 +20,7 @@
 import os
 import pathlib
 import re
+import re
 import shutil
 import warnings
 
@@ -31,7 +32,7 @@
 
 DEFAULT_PYTHON_VERSION = "3.8"
 
-UNIT_TEST_PYTHON_VERSIONS = ["3.6", "3.7", "3.8", "3.9", "3.10"]
+UNIT_TEST_PYTHON_VERSIONS = ["3.7", "3.8", "3.9", "3.10"]
 UNIT_TEST_STANDARD_DEPENDENCIES = [
     "mock",
     "asyncmock",
@@ -477,3 +478,90 @@ def docfx(session):
         os.path.join("docs", ""),
         os.path.join("docs", "_build", "html", ""),
     )
+
+
+@nox.session(python=SYSTEM_TEST_PYTHON_VERSIONS)
+def prerelease_deps(session):
+    """Run all tests with prerelease versions of dependencies installed."""
+
+    # Install all dependencies
+    session.install("-e", ".[all, tests, tracing]")
+    session.install(*UNIT_TEST_STANDARD_DEPENDENCIES)
+    system_deps_all = (
+        SYSTEM_TEST_STANDARD_DEPENDENCIES
+        + SYSTEM_TEST_EXTERNAL_DEPENDENCIES
+        + SYSTEM_TEST_EXTRAS
+    )
+    session.install(*system_deps_all)
+
+    # Because we test minimum dependency versions on the minimum Python
+    # version, the first version we test with in the unit tests sessions has a
+    # constraints file containing all dependencies and extras.
+    with open(
+        CURRENT_DIRECTORY
+        / "testing"
+        / f"constraints-{UNIT_TEST_PYTHON_VERSIONS[0]}.txt",
+        encoding="utf-8",
+    ) as constraints_file:
+        constraints_text = constraints_file.read()
+
+    # Ignore leading whitespace and comment lines.
+    constraints_deps = [
+        match.group(1)
+        for match in re.finditer(
+            r"^\s*(\S+)(?===\S+)", constraints_text, flags=re.MULTILINE
+        )
+    ]
+
+    session.install(*constraints_deps)
+
+    if os.path.exists("samples/snippets/requirements.txt"):
+        session.install("-r", "samples/snippets/requirements.txt")
+
+    if os.path.exists("samples/snippets/requirements-test.txt"):
+        session.install("-r", "samples/snippets/requirements-test.txt")
+
+    prerel_deps = [
+        "protobuf",
+        # dependency of grpc
+        "six",
+        "googleapis-common-protos",
+        "grpcio",
+        "grpcio-status",
+        "google-api-core",
+        "proto-plus",
+        "google-cloud-testutils",
+        # dependencies of google-cloud-testutils"
+        "click",
+    ]
+
+    for dep in prerel_deps:
+        session.install("--pre", "--no-deps", "--upgrade", dep)
+
+    # Remaining dependencies
+    other_deps = [
+        "requests",
+        "google-auth",
+    ]
+    session.install(*other_deps)
+
+    # Print out prerelease package versions
+    session.run(
+        "python", "-c", "import google.protobuf; print(google.protobuf.__version__)"
+    )
+    session.run("python", "-c", "import grpc; print(grpc.__version__)")
+
+    session.run("py.test", "tests/unit")
+
+    system_test_path = os.path.join("tests", "system.py")
+    system_test_folder_path = os.path.join("tests", "system")
+
+    # Only run system tests if found.
+    if os.path.exists(system_test_path) or os.path.exists(system_test_folder_path):
+        session.run("py.test", "tests/system")
+
+    snippets_test_path = os.path.join("samples", "snippets")
+
+    # Only run samples tests if found.
+    if os.path.exists(snippets_test_path):
+        session.run("py.test", "samples/snippets")

.kokoro/samples/python3.6/presubmit.cfg

@@ -33,7 +33,6 @@
     "3.10": ["tests", "geography"],
 }
 templated_files = common.py_library(
-    unit_test_python_versions=["3.6", "3.7", "3.8", "3.9", "3.10"],
     system_test_python_versions=["3.8", "3.10"],
     cov_level=100,
     unit_test_extras=extras,
@@ -47,6 +46,7 @@
     "docs/multiprocessing.rst",
     # exclude gh actions as credentials are needed for tests
     ".github/workflows",
+    "README.rst",
 ])
 
 # ----------------------------------------------------------------------------

.kokoro/test-samples-impl.sh

@@ -89,7 +89,7 @@ def get_pytest_env_vars() -> Dict[str, str]:
 
 # DO NOT EDIT - automatically generated.
 # All versions used to test samples.
-ALL_VERSIONS = ["3.6", "3.7", "3.8", "3.9", "3.10"]
+ALL_VERSIONS = ["3.7", "3.8", "3.9", "3.10"]
 
 # Any default versions that should be ignored.
 IGNORED_VERSIONS = TEST_CONFIG["ignored_versions"]

CONTRIBUTING.rst

@@ -12,7 +12,7 @@ Install Dependencies
    .. _Python Development Environment Setup Guide:
        https://cloud.google.com/python/setup
 
-#. Create a virtualenv. Samples are compatible with Python 3.6+.
+#. Create a virtualenv. Samples are compatible with Python 3.7+.
 
     .. code-block:: bash
 

README.rst

@@ -69,7 +69,6 @@ def readme():
         "License :: OSI Approved :: MIT License",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
@@ -96,7 +95,7 @@ def readme():
         "future",
     ],
     extras_require=extras,
-    python_requires=">=3.6, <3.11",
+    python_requires=">=3.7, <3.11",
     tests_require=["packaging", "pytz"],
     entry_points={
         "sqlalchemy.dialects": ["bigquery = sqlalchemy_bigquery:BigQueryDialect"]