Drop Python 3.8

[stankudrow]

Fixes #355

Checklist:

• Add tests that demonstrate the correct behavior of the change. Tests should fail without the change.
• Add or update relevant docs, in the docs folder and in code.
• Ensure PR doesn't contain untouched code reformatting: spaces, etc.
• Run flake8 and fix issues.
• Run pytest no tests failed. See https://clickhouse-sqlalchemy.readthedocs.io/en/latest/development.html.

[stankudrow]

The lion's share of the changes derives from pyupgrade --py38-plus ... commands.

[9en9i]

Hi, are there any issues with this pull request? Can I help with anything?

[9en9i]

At the very least, I see outdated metadata in setup.py, it still specifies Python 3.7.

[9en9i]

@xzkostyan What do you think about this pull request? Can we refine it? How? So that it can be merged

[stankudrow]

Hi, are there any issues with this pull request? Can I help with anything?

Hello.

Yeah, you can help in reviewing or even coathoring (or both). First, could you highlight what needs fixing, please?

[9en9i]

I reviewed all the changes, and it looks good! Just some cosmetic updates thanks to pyupgrade.
The only thing is, I’m not sure that a version dropping support for Python 3.8 should be a patch release.

[stankudrow]

Ah, there are problems to be solved first:

tests/types/test_json.py .F                              [ 98%]
tests/types/test_numeric.py ......                       [100%]

=========================== FAILURES ===========================
____________ JSONTestCaseNative.test_select_insert _____________

self = <clickhouse_sqlalchemy.drivers.native.connector.Cursor object at 0x7b54060c9520>
operation = 'CREATE TABLE test (x JSON) ENGINE = Memory'
parameters = {}
context = <clickhouse_sqlalchemy.drivers.native.base.ClickHouseExecutionContext object at 0x7b54060c91c0>

    def execute(self, operation, parameters=None, context=None):
        self._reset_state()
        self._begin_query()
    
        try:
            execute, execute_kwargs = self._prepare(context)
>           response = execute(
                operation, params=parameters, with_column_types=True,
                **execute_kwargs
            )

clickhouse_sqlalchemy/drivers/native/connector.py:153: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
.venv/lib/python3.9/site-packages/clickhouse_driver/client.py:382: in execute
    rv = self.process_ordinary_query(
.venv/lib/python3.9/site-packages/clickhouse_driver/client.py:580: in process_ordinary_query
    return self.receive_result(with_column_types=with_column_types,
.venv/lib/python3.9/site-packages/clickhouse_driver/client.py:212: in receive_result
    return result.get_result()
.venv/lib/python3.9/site-packages/clickhouse_driver/result.py:50: in get_result
    for packet in self.packet_generator:
.venv/lib/python3.9/site-packages/clickhouse_driver/client.py:228: in packet_generator
    packet = self.receive_packet()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <clickhouse_driver.client.Client object at 0x7b54063ca760>

    def receive_packet(self):
        packet = self.connection.receive_packet()
    
        if packet.type == ServerPacketTypes.EXCEPTION:
>           raise packet.exception
E           clickhouse_driver.errors.ServerException: Code: 44.
E           DB::Exception: Cannot create column with type 'JSON' because experimental JSON type is not allowed. Set setting allow_experimental_json_type = 1 in order to allow it. Stack trace:
E           
E           0. DB::Exception::Exception(DB::Exception::MessageMasked&&, int, bool) @ 0x000000000cf7c73b
E           1. DB::Exception::Exception(PreformattedMessage&&, int) @ 0x0000000007ea788c
E           2. DB::Exception::Exception<String>(int, FormatStringHelperImpl<std::type_identity<String>::type>, String&&) @ 0x0000000007ea73cb
E           3. DB::validateDataType(std::shared_ptr<DB::IDataType const> const&, DB::DataTypeValidationSettings const&)::$_0::operator()(DB::IDataType const&) const (.llvm.2336510096372259121) @ 0x00000000117810cd
E           4. DB::InterpreterCreateQuery::getTablePropertiesAndNormalizeCreateQuery(DB::ASTCreateQuery&, DB::LoadingStrictnessLevel) const @ 0x000000001114e26f
E           5. DB::InterpreterCreateQuery::createTable(DB::ASTCreateQuery&) @ 0x00000000111550bf
E           6. DB::InterpreterCreateQuery::execute() @ 0x0000000011167bb0
E           7. DB::executeQueryImpl(char const*, char const*, std::shared_ptr<DB::Context>, DB::QueryFlags, DB::QueryProcessingStage::Enum, DB::ReadBuffer*) @ 0x00000000117351c3
E           8. DB::executeQuery(String const&, std::shared_ptr<DB::Context>, DB::QueryFlags, DB::QueryProcessingStage::Enum) @ 0x0000000011730ffa
E           9. DB::TCPHandler::runImpl() @ 0x0000000012922614
E           10. DB::TCPHandler::run() @ 0x000000001293da78
E           11. Poco::Net::TCPServerConnection::start() @ 0x000000001580b827
E           12. Poco::Net::TCPServerDispatcher::run() @ 0x000000001580bcb9
E           13. Poco::PooledThread::run() @ 0x00000000157d8821
E           14. Poco::ThreadImpl::runnableEntry(void*) @ 0x00000000157d6ddd
E           15. ? @ 0x0000714ceb0b3609
E           16. ? @ 0x0000714ceafd8353

.venv/lib/python3.9/site-packages/clickhouse_driver/client.py:245: ServerException

During handling of the above exception, another exception occurred:

self = <tests.types.test_json.JSONTestCaseNative testMethod=test_select_insert>

    def test_select_insert(self):
        data = {'k1': 1, 'k2': '2', 'k3': True}
    
        self.table.drop(bind=self.session.bind, if_exists=True)
        try:
            # http session is unsupport
            self.session.execute(
                text('SET allow_experimental_object_type = 1;')
            )
>           self.session.execute(text(self.compile(CreateTable(self.table))))

tests/types/test_json.py:48: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
.venv/lib/python3.9/site-packages/sqlalchemy/orm/session.py:2229: in execute
    return self._execute_internal(
.venv/lib/python3.9/site-packages/sqlalchemy/orm/session.py:2133: in _execute_internal
    result = conn.execute(
.venv/lib/python3.9/site-packages/sqlalchemy/engine/base.py:1414: in execute
    return meth(
.venv/lib/python3.9/site-packages/sqlalchemy/sql/elements.py:489: in _execute_on_connection
    return connection._execute_clauseelement(
.venv/lib/python3.9/site-packages/sqlalchemy/engine/base.py:1638: in _execute_clauseelement
    ret = self._execute_context(
.venv/lib/python3.9/site-packages/sqlalchemy/engine/base.py:1842: in _execute_context
    return self._exec_single_context(
.venv/lib/python3.9/site-packages/sqlalchemy/engine/base.py:1983: in _exec_single_context
    self._handle_dbapi_exception(
.venv/lib/python3.9/site-packages/sqlalchemy/engine/base.py:2328: in _handle_dbapi_exception
    raise exc_info[1].with_traceback(exc_info[2])
.venv/lib/python3.9/site-packages/sqlalchemy/engine/base.py:1964: in _exec_single_context
    self.dialect.do_execute(
clickhouse_sqlalchemy/drivers/base.py:499: in do_execute
    cursor.execute(statement, parameters, context=context)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <clickhouse_sqlalchemy.drivers.native.connector.Cursor object at 0x7b54060c9520>
operation = 'CREATE TABLE test (x JSON) ENGINE = Memory'
parameters = {}
context = <clickhouse_sqlalchemy.drivers.native.base.ClickHouseExecutionContext object at 0x7b54060c91c0>

    def execute(self, operation, parameters=None, context=None):
        self._reset_state()
        self._begin_query()
    
        try:
            execute, execute_kwargs = self._prepare(context)
            response = execute(
                operation, params=parameters, with_column_types=True,
                **execute_kwargs
            )
    
        except DriverError as orig:
>           raise DatabaseException(orig)
E           clickhouse_sqlalchemy.exceptions.DatabaseException: Orig exception: Code: 44.
E           DB::Exception: Cannot create column with type 'JSON' because experimental JSON type is not allowed. Set setting allow_experimental_json_type = 1 in order to allow it. Stack trace:
E           
E           0. DB::Exception::Exception(DB::Exception::MessageMasked&&, int, bool) @ 0x000000000cf7c73b
E           1. DB::Exception::Exception(PreformattedMessage&&, int) @ 0x0000000007ea788c
E           2. DB::Exception::Exception<String>(int, FormatStringHelperImpl<std::type_identity<String>::type>, String&&) @ 0x0000000007ea73cb
E           3. DB::validateDataType(std::shared_ptr<DB::IDataType const> const&, DB::DataTypeValidationSettings const&)::$_0::operator()(DB::IDataType const&) const (.llvm.2336510096372259121) @ 0x00000000117810cd
E           4. DB::InterpreterCreateQuery::getTablePropertiesAndNormalizeCreateQuery(DB::ASTCreateQuery&, DB::LoadingStrictnessLevel) const @ 0x000000001114e26f
E           5. DB::InterpreterCreateQuery::createTable(DB::ASTCreateQuery&) @ 0x00000000111550bf
E           6. DB::InterpreterCreateQuery::execute() @ 0x0000000011167bb0
E           7. DB::executeQueryImpl(char const*, char const*, std::shared_ptr<DB::Context>, DB::QueryFlags, DB::QueryProcessingStage::Enum, DB::ReadBuffer*) @ 0x00000000117351c3
E           8. DB::executeQuery(String const&, std::shared_ptr<DB::Context>, DB::QueryFlags, DB::QueryProcessingStage::Enum) @ 0x0000000011730ffa
E           9. DB::TCPHandler::runImpl() @ 0x0000000012922614
E           10. DB::TCPHandler::run() @ 0x000000001293da78
E           11. Poco::Net::TCPServerConnection::start() @ 0x000000001580b827
E           12. Poco::Net::TCPServerDispatcher::run() @ 0x000000001580bcb9
E           13. Poco::PooledThread::run() @ 0x00000000157d8821
E           14. Poco::ThreadImpl::runnableEntry(void*) @ 0x00000000157d6ddd
E           15. ? @ 0x0000714ceb0b3609
E           16. ? @ 0x0000714ceafd8353

clickhouse_sqlalchemy/drivers/native/connector.py:159: DatabaseException
======================= warnings summary =======================
tests/types/test_enum16.py:11
  .../clickhouse-sqlalchemy/tests/types/test_enum16.py:11: PytestCollectionWarning: cannot collect test class 'TestEnum' because it has a __new__ constructor (from: tests/types/test_enum16.py)
    class TestEnum(enum.IntEnum):

tests/types/test_enum8.py:11
  .../clickhouse-sqlalchemy/tests/types/test_enum8.py:11: PytestCollectionWarning: cannot collect test class 'TestEnum' because it has a __new__ constructor (from: tests/types/test_enum8.py)
    class TestEnum(enum.IntEnum):

tests/types/test_date32.py::Date32TestCaseHTTP::test_select_insert
  .../clickhouse-sqlalchemy/tests/types/test_date32.py:42: SAWarning: Class Select will not make use of SQL compilation caching as it does not set the 'inherit_cache' attribute to ``True``.  This can have significant performance implications including some performance degradations in comparison to prior SQLAlchemy versions.  Set this attribute to True if this object can make use of the cache key generated by the superclass.  Alternatively, this attribute may be set to False which will disable this warning. (Background on this error at: https://sqlalche.me/e/20/cprf)
    result = self.session.execute(self.table.select()).scalar()

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html

@9en9i , the #357 must be dealt first, you help is highly appreciated.

I'll convert this PR to draft again.