Remove jython code, remove all jython / pypy symbols

Removed all dialect code related to support for Jython and zxJDBC. Jython
has not been supported by SQLAlchemy for many years and it is not expected
that the current zxJDBC code is at all functional; for the moment it just
takes up space and adds confusion by showing up in documentation. At the
moment, it appears that Jython has achieved Python 2.7 support in its
releases but not Python 3.   If Jython were to be supported again, the form
it should take is against the Python 3 version of Jython, and the various
zxJDBC stubs for various backends should be implemented as a third party
dialect.

Additionally modernized logic that distinguishes between "cpython"
and "pypy" to instead look at platform.python_distribution() which
reliably tells us if we are cPython or not; all booleans which
previously checked for pypy and sometimes jython are now converted
to be "not cpython", this impacts the test suite for tests that are
cPython centric.

Fixes: #5094
Change-Id: I226cb55827f997daf6b4f4a755c18e7f4eb8d9ad

2 files changed, 7 insertions, 5 deletions

diff --git a/lib/sqlalchemy/util/__init__.py b/lib/sqlalchemy/util/__init__.py
index a19636f62..30e384027 100644
--- a/lib/sqlalchemy/util/__init__.py
+++ b/lib/sqlalchemy/util/__init__.py
@@ -53,12 +53,12 @@ from .compat import cmp  # noqa
 from .compat import cpython  # noqa
 from .compat import decode_backslashreplace  # noqa
 from .compat import dottedgetter  # noqa
+from .compat import has_refcount_gc  # noqa
 from .compat import inspect_getfullargspec  # noqa
 from .compat import int_types  # noqa
 from .compat import iterbytes  # noqa
 from .compat import itertools_filter  # noqa
 from .compat import itertools_filterfalse  # noqa
-from .compat import jython  # noqa
 from .compat import namedtuple  # noqa
 from .compat import nested  # noqa
 from .compat import next  # noqa
@@ -69,7 +69,6 @@ from .compat import py2k  # noqa
 from .compat import py33  # noqa
 from .compat import py36  # noqa
 from .compat import py3k  # noqa
-from .compat import pypy  # noqa
 from .compat import quote_plus  # noqa
 from .compat import raise_from_cause  # noqa
 from .compat import reduce  # noqa
diff --git a/lib/sqlalchemy/util/compat.py b/lib/sqlalchemy/util/compat.py
index 2cb5db5d4..ea9ac0f11 100644
--- a/lib/sqlalchemy/util/compat.py
+++ b/lib/sqlalchemy/util/compat.py
@@ -11,6 +11,7 @@ import collections
 import contextlib
 import inspect
 import operator
+import platform
 import sys
 
 
@@ -21,10 +22,12 @@ py32 = sys.version_info >= (3, 2)
 py3k = sys.version_info >= (3, 0)
 py2k = sys.version_info < (3, 0)
 py265 = sys.version_info >= (2, 6, 5)
-jython = sys.platform.startswith("java")
-pypy = hasattr(sys, "pypy_version_info")
+
+
+cpython = platform.python_implementation() == "CPython"
 win32 = sys.platform.startswith("win")
-cpython = not pypy and not jython  # TODO: something better for this ?
+
+has_refcount_gc = bool(cpython)
 
 contextmanager = contextlib.contextmanager
 dottedgetter = operator.attrgetter