Change-Id: I6a71f4924d046cf306961c58dffccf21e9c03911
(cherry picked from commit 6f270fb0e344016ce526e0a1ecb3e3de9ffd1e3b)

Fixed a regression introduced in version 1.2 where a refactor
of the :class:`.SQLAlchemyError` base exception class introduced an
inappropriate coercion of a plain string message into Unicode under
python 2k, which is not handled by the Python interpreter for characters
outside of the platform's encoding (typically ascii).  The
:class:`.SQLAlchemyError` class now passes a bytestring through under
Py2K for ``__str__()`` as is the behavior of exception objects in general
under Py2K, does a safe coercion to unicode utf-8 with
backslash fallback for ``__unicode__()``.  For Py3K the message is
typically unicode already, but if not is again safe-coerced with utf-8
with backslash fallback for the ``__str__()`` method.

Fixes: #4429
Change-Id: I2289da3f2c45c7d0041fa43d838958f7614defc3
(cherry picked from commit 2db54ee92ebd0970f52b271e152a6df9b563693f)

Applied on top of a pure run of black -l 79 in
I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9,  this set of changes
resolves all remaining flake8 conditions for those codes
we have enabled in setup.cfg.

Included are resolutions for all remaining flake8 issues
including shadowed builtins, long lines, import order, unused
imports, duplicate imports, and docstring issues.

Change-Id: I4f72d3ba1380dd601610ff80b8fb06a2aff8b0fe

This is a straight reformat run using black as is, with no edits
applied at all.

The black run will format code consistently, however in
some cases that are prevalent in SQLAlchemy code it produces
too-long lines.   The too-long lines will be resolved in the
following commit that will resolve all remaining flake8 issues
including shadowed builtins, long lines, import order, unused
imports, duplicate imports, and docstring issues.

Change-Id: I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9

Started importing "collections" from "collections.abc" under Python 3.3 and
greater for Python 3.8 compatibility.  Pull request courtesy Nathaniel
Knight.

In Python 3.3, the abstract base classes (Iterable, Mapping, etc.)
were moved from the `collections` module and put in the
`collections.abc` module. They remain in the `collections` module for
backwards compatibility, and will until Python 3.8.

This commit adds a variable (`collections_abc`) to the `util/compat`
module, which will be the `collections` module for Python < 3.3 and
before, or the `collections.abc` module for Python >= 3.3. It also
uses the new variable, getting rid of some deprecation warnings that
were seen when running under Python 3.7.

Change-Id: I2d1c0ef97c8ecac7af152cc56263422a40faa6bb
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/464
(cherry picked from commit a59c3b8f302a34ab037ec445b7452b1f353b91af)

Replaced the usage of inspect.formatargspec() with a vendored version
copied from the Python standard library, as inspect.formatargspec()
is deprecated and as of Python 3.7.0 is emitting a warning.

Change-Id: I751652fac7f605a3a10b547ba8c5f34fef1de945
Fixes: #4291
(cherry picked from commit 536d5187a038a44aec624dd2a99792f49dec82ed)

Change-Id: I3ef36bfd0cb0ba62b3123c8cf92370a43156cf8f

Corrects some warnings and adds tox config.  Adds DeprecationWarning
to the error category.   Large sweep for string literals w/ backslashes
as this is common in docstrings

Co-authored-by: Andrii Soldatenko
Fixes: #3886
Change-Id: Ia7c838dfbbe70b262622ed0803d581edc736e085
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/337

Change-Id: I4e8c2aa8fe817bb2af8707410fa0201f938781de

would be turned into a list of individual characters.  This would
impact among other things using the :meth:`.Query.get` method
on a primary key that's a bytes object.
fixes #3660