From: Mike Bayer Date: Thu, 7 May 2020 14:53:15 +0000 (-0400) Subject: Disable "check unicode returns" under Python 3 X-Git-Tag: rel_1_4_0b1~325 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=af0e59ff16a2a02ec5dc1195212236e63fd941a7;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git Disable "check unicode returns" under Python 3 Disabled the "unicode returns" check that runs on dialect startup when running under Python 3, which for many years has occurred in order to test the current DBAPI's behavior for whether or not it returns Python Unicode or Py2K strings for the VARCHAR and NVARCHAR datatypes. The check still occurs by default under Python 2, however the mechanism to test the behavior will be removed in SQLAlchemy 2.0 when Python 2 support is also removed. This logic was very effective when it was needed, however now that Python 3 is standard, all DBAPIs are expected to return Python 3 strings for character datatypes. In the unlikely case that a third party DBAPI does not support this, the conversion logic within :class:`.String` is still available and the third party dialect may specify this in its upfront dialect flags by setting the dialect level flag ``returns_unicode_strings`` to one of :attr:`.String.RETURNS_CONDITIONAL` or :attr:`.String.RETURNS_BYTES`, both of which will enable Unicode conversion even under Python 3. As part of this change, disabling testing of the doctest tutorials under Python 2. Fixes: #5315 Change-Id: I1260e894611409d3b7fe1a92bd90c52043bbcf19 --- diff --git a/doc/build/changelog/unreleased_14/5315.rst b/doc/build/changelog/unreleased_14/5315.rst new file mode 100644 index 0000000000..ff0073c807 --- /dev/null +++ b/doc/build/changelog/unreleased_14/5315.rst @@ -0,0 +1,21 @@ +.. change:: + :tags: change, performance, engine, py3k + :tickets: 5315 + + Disabled the "unicode returns" check that runs on dialect startup when + running under Python 3, which for many years has occurred in order to test + the current DBAPI's behavior for whether or not it returns Python Unicode + or Py2K strings for the VARCHAR and NVARCHAR datatypes. The check still + occurs by default under Python 2, however the mechanism to test the + behavior will be removed in SQLAlchemy 2.0 when Python 2 support is also + removed. + + This logic was very effective when it was needed, however now that Python 3 + is standard, all DBAPIs are expected to return Python 3 strings for + character datatypes. In the unlikely case that a third party DBAPI does + not support this, the conversion logic within :class:`.String` is still + available and the third party dialect may specify this in its upfront + dialect flags by setting the dialect level flag ``returns_unicode_strings`` + to one of :attr:`.String.RETURNS_CONDITIONAL` or + :attr:`.String.RETURNS_BYTES`, both of which will enable Unicode conversion + even under Python 3. diff --git a/doc/build/core/tutorial.rst b/doc/build/core/tutorial.rst index 1f475abe34..a504f85785 100644 --- a/doc/build/core/tutorial.rst +++ b/doc/build/core/tutorial.rst @@ -150,7 +150,7 @@ each table first before creating, so it's safe to call multiple times: .. sourcecode:: pycon+sql {sql}>>> metadata.create_all(engine) - SE... + PRAGMA... CREATE TABLE users ( id INTEGER NOT NULL, name VARCHAR, diff --git a/doc/build/orm/tutorial.rst b/doc/build/orm/tutorial.rst index e77964a7b6..c08daa7fd6 100644 --- a/doc/build/orm/tutorial.rst +++ b/doc/build/orm/tutorial.rst @@ -209,7 +209,6 @@ the actual ``CREATE TABLE`` statement: .. sourcecode:: python+sql >>> Base.metadata.create_all(engine) - SELECT ... PRAGMA main.table_info("users") () PRAGMA temp.table_info("users") diff --git a/lib/sqlalchemy/engine/default.py b/lib/sqlalchemy/engine/default.py index 20f7311160..d9b4cdda69 100644 --- a/lib/sqlalchemy/engine/default.py +++ b/lib/sqlalchemy/engine/default.py @@ -94,12 +94,12 @@ class DefaultDialect(interfaces.Dialect): if util.py3k: supports_unicode_statements = True supports_unicode_binds = True - returns_unicode_strings = True + returns_unicode_strings = sqltypes.String.RETURNS_UNICODE description_encoding = None else: supports_unicode_statements = False supports_unicode_binds = False - returns_unicode_strings = False + returns_unicode_strings = sqltypes.String.RETURNS_UNKNOWN description_encoding = "use_encoding" name = "default" @@ -325,7 +325,14 @@ class DefaultDialect(interfaces.Dialect): except NotImplementedError: self.default_isolation_level = None - self.returns_unicode_strings = self._check_unicode_returns(connection) + if self.returns_unicode_strings is sqltypes.String.RETURNS_UNKNOWN: + if util.py3k: + raise exc.InvalidRequestError( + "RETURNS_UNKNOWN is unsupported in Python 3" + ) + self.returns_unicode_strings = self._check_unicode_returns( + connection + ) if ( self.description_encoding is not None @@ -415,9 +422,13 @@ class DefaultDialect(interfaces.Dialect): results = {check_unicode(test) for test in tests} if results.issuperset([True, False]): - return "conditional" + return sqltypes.String.RETURNS_CONDITIONAL else: - return results == {True} + return ( + sqltypes.String.RETURNS_UNICODE + if results == {True} + else sqltypes.String.RETURNS_BYTES + ) def _check_unicode_description(self, connection): # all DBAPIs on Py2K return cursor.description as encoded diff --git a/lib/sqlalchemy/sql/sqltypes.py b/lib/sqlalchemy/sql/sqltypes.py index a65989e931..8684a79226 100644 --- a/lib/sqlalchemy/sql/sqltypes.py +++ b/lib/sqlalchemy/sql/sqltypes.py @@ -135,6 +135,67 @@ class String(Concatenable, TypeEngine): __visit_name__ = "string" + RETURNS_UNICODE = util.symbol( + "RETURNS_UNICODE", + """Indicates that the DBAPI returns Python Unicode for VARCHAR, + NVARCHAR, and other character-based datatypes in all cases. + + This is the default value for + :attr:`.DefaultDialect.returns_unicode_strings` under Python 3. + + .. versionadded:: 1.4 + + """, + ) + + RETURNS_BYTES = util.symbol( + "RETURNS_BYTES", + """Indicates that the DBAPI returns byte objects under Python 3 + or non-Unicode string objects under Python 2 for VARCHAR, NVARCHAR, + and other character-based datatypes in all cases. + + This may be applied to the + :attr:`.DefaultDialect.returns_unicode_strings` attribute. + + .. versionadded:: 1.4 + + """, + ) + + RETURNS_CONDITIONAL = util.symbol( + "RETURNS_CONDITIONAL", + """Indicates that the DBAPI may return Unicode or bytestrings for + VARCHAR, NVARCHAR, and other character-based datatypes, and that + SQLAlchemy's default String datatype will need to test on a per-row + basis for Unicode or bytes. + + This may be applied to the + :attr:`.DefaultDialect.returns_unicode_strings` attribute. + + .. versionadded:: 1.4 + + """, + ) + + RETURNS_UNKNOWN = util.symbol( + "RETURNS_UNKNOWN", + """Indicates that the dialect should test on first connect what the + string-returning behavior of character-based datatypes is. + + This is the default value for DefaultDialect.unicode_returns under + Python 2. + + This may be applied to the + :attr:`.DefaultDialect.returns_unicode_strings` attribute under + Python 2 only. The value is disallowed under Python 3. + + .. versionadded:: 1.4 + + .. deprecated:: 1.4 This value will be removed in SQLAlchemy 2.0. + + """, + ) + @util.deprecated_params( convert_unicode=( "1.3", @@ -293,12 +354,13 @@ class String(Concatenable, TypeEngine): def result_processor(self, dialect, coltype): wants_unicode = self._expect_unicode or dialect.convert_unicode needs_convert = wants_unicode and ( - dialect.returns_unicode_strings is not True + dialect.returns_unicode_strings is not String.RETURNS_UNICODE or self._expect_unicode in ("force", "force_nocheck") ) needs_isinstance = ( needs_convert and dialect.returns_unicode_strings + in (String.RETURNS_CONDITIONAL, String.RETURNS_UNICODE,) and self._expect_unicode != "force_nocheck" ) if needs_convert: diff --git a/test/base/test_tutorials.py b/test/base/test_tutorials.py index 3ac7913f9d..69f9f7e900 100644 --- a/test/base/test_tutorials.py +++ b/test/base/test_tutorials.py @@ -12,6 +12,8 @@ from sqlalchemy.testing import fixtures class DocTest(fixtures.TestBase): + __requires__ = ("python3",) + def _setup_logger(self): rootlogger = logging.getLogger("sqlalchemy.engine.Engine") diff --git a/test/engine/test_execute.py b/test/engine/test_execute.py index a8d7b397ec..285dd2acf7 100644 --- a/test/engine/test_execute.py +++ b/test/engine/test_execute.py @@ -648,6 +648,32 @@ class ExecuteTest(fixtures.TablesTest): eng2 = eng.execution_options(foo="bar") assert eng2._has_events + def test_works_after_dispose(self): + eng = create_engine(testing.db.url) + for i in range(3): + eq_(eng.scalar(select([1])), 1) + eng.dispose() + + def test_works_after_dispose_testing_engine(self): + eng = engines.testing_engine() + for i in range(3): + eq_(eng.scalar(select([1])), 1) + eng.dispose() + + +class UnicodeReturnsTest(fixtures.TestBase): + @testing.requires.python3 + def test_unicode_test_not_in_python3(self): + eng = engines.testing_engine() + eng.dialect.returns_unicode_strings = String.RETURNS_UNKNOWN + + assert_raises_message( + tsa.exc.InvalidRequestError, + "RETURNS_UNKNOWN is unsupported in Python 3", + eng.connect, + ) + + @testing.requires.python2 def test_unicode_test_fails_warning(self): class MockCursor(engines.DBAPIProxyCursor): def execute(self, stmt, params=None, **kw): @@ -663,21 +689,9 @@ class ExecuteTest(fixtures.TablesTest): eng.connect() # because plain varchar passed, we don't know the correct answer - eq_(eng.dialect.returns_unicode_strings, "conditional") + eq_(eng.dialect.returns_unicode_strings, String.RETURNS_CONDITIONAL) eng.dispose() - def test_works_after_dispose(self): - eng = create_engine(testing.db.url) - for i in range(3): - eq_(eng.scalar(select([1])), 1) - eng.dispose() - - def test_works_after_dispose_testing_engine(self): - eng = engines.testing_engine() - for i in range(3): - eq_(eng.scalar(select([1])), 1) - eng.dispose() - class ConvenienceExecuteTest(fixtures.TablesTest): __backend__ = True diff --git a/test/engine/test_reconnect.py b/test/engine/test_reconnect.py index f0d0a9b2fb..48e3248064 100644 --- a/test/engine/test_reconnect.py +++ b/test/engine/test_reconnect.py @@ -950,6 +950,16 @@ class CursorErrTest(fixtures.TestBase): url, options=dict(module=dbapi, _initialize=initialize) ) eng.pool.logger = Mock() + + def get_default_schema_name(connection): + try: + cursor = connection.connection.cursor() + connection._cursor_execute(cursor, "statement", {}) + cursor.close() + except exc.DBAPIError: + util.warn("Exception attempting to detect") + + eng.dialect._get_default_schema_name = get_default_schema_name return eng def test_cursor_explode(self): diff --git a/test/sql/test_types.py b/test/sql/test_types.py index e0c1359b46..a0c4ee0220 100644 --- a/test/sql/test_types.py +++ b/test/sql/test_types.py @@ -86,6 +86,7 @@ from sqlalchemy.testing.schema import Table from sqlalchemy.testing.util import picklers from sqlalchemy.testing.util import round_decimal from sqlalchemy.util import OrderedDict +from sqlalchemy.util import u def _all_dialect_modules(): @@ -763,6 +764,50 @@ class UserDefinedTest( eq_(a.dialect_specific_args["bar"], "bar") +class StringConvertUnicodeTest(fixtures.TestBase): + @testing.combinations((Unicode,), (String,), argnames="datatype") + @testing.combinations((True,), (False,), argnames="convert_unicode") + @testing.combinations( + (String.RETURNS_CONDITIONAL,), + (String.RETURNS_BYTES,), + (String.RETURNS_UNICODE), + argnames="returns_unicode_strings", + ) + def test_convert_unicode( + self, datatype, convert_unicode, returns_unicode_strings + ): + s1 = datatype() + dialect = mock.Mock( + returns_unicode_strings=returns_unicode_strings, + encoding="utf-8", + convert_unicode=convert_unicode, + ) + + proc = s1.result_processor(dialect, None) + + string = u("méil") + bytestring = string.encode("utf-8") + + if ( + datatype is Unicode or convert_unicode + ) and returns_unicode_strings in ( + String.RETURNS_CONDITIONAL, + String.RETURNS_BYTES, + ): + eq_(proc(bytestring), string) + + if returns_unicode_strings is String.RETURNS_CONDITIONAL: + eq_(proc(string), string) + else: + if util.py3k: + # trying to decode a unicode + assert_raises(TypeError, proc, string) + else: + assert_raises(UnicodeEncodeError, proc, string) + else: + is_(proc, None) + + class TypeCoerceCastTest(fixtures.TablesTest): __backend__ = True