This adds the very small plugin flake8-import-single which
will prevent us from having an import with more than one symbol
on a line.

Flake8 by itself prevents this pattern with E401:

import collections, os, sys

However does not do anything with this:

from sqlalchemy import Column, text

Both statements have the same issues generating merge artifacts
as well as presenting a manual decision to be made.   While
zimports generally cleans up such imports at the top level, we
don't enforce zimports / pre-commit use.

the plugin finds the same issue for imports that are inside of
test methods.   We shouldn't usually have imports in test methods
so most of them here are moved to be top level.

The version is pinned at 0.1.5; the project seems to have no
activity since 2019, however there are three 0.1.6dev releases
on pypi which stopped in September 2019, they seem to be
experiments with packaging.  The source for 0.1.5
is extremely simple and only reveals one method to flake8
(the run() method).

Change-Id: Icea894e43bad9c0b5d4feb5f49c6c666d6ea6aa1

Change-Id: If278ea170e0a17b1e8ace2d470fb2fbdb7a6e9c1
References: #9370
References: #9365

For consistency with the prominent ORM concept :class:`_orm.Mapped`, the
names of the dictionary-oriented collections,
:func:`_orm.attribute_mapped_collection`,
:func:`_orm.column_mapped_collection`, and :class:`_orm.MappedCollection`,
are changed to :func:`_orm.attribute_keyed_dict`,
:func:`_orm.column_keyed_dict` and :class:`_orm.KeyFuncDict`, using the
phrase "dict" to minimize any confusion against the term "mapped". The old
names will remain indefinitely with no schedule for removal.

Docs here are also updated for typing as we can type
these collections as ``Mapped[dict[str, cls]]``, don't need
KeyFuncDict / MappedCollection for these

Fixes: #8608
Change-Id: Ib5cf63e0aef1c389e023a75e454bb21f9d779b54

Change-Id: I8172fdcc3103ff92aa049827728484c8779af6b7

References: #4600
Change-Id: I2a62ddfe00bc562720f0eae700a497495d7a987a

this was using a long-ago not working form of case().

Change-Id: I39c7cec2e46dd215d7acb7d3ee6debd30fa1ec34

It's better, the majority of these changes look more readable to me.
also found some docstrings that had formatting / quoting issues.

Change-Id: I582a45fde3a5648b2f36bab96bad56881321899b

<!-- Provide a general summary of your proposed changes in the Title field above -->

### Description
<!-- Describe your changes in detail -->
Remove print statements

### Checklist
<!-- go over following points. check them with an `x` if they do apply, (they turn into clickable checkboxes once the PR is submitted, so no need to do everything at once)

-->

This pull request is:

- [X] A documentation / typographical error fix
	- Good to go, no issue or tests are needed
- [ ] A short code fix
	- please include the issue number, and create an issue if none exists, which
	  must include a complete example of the issue.  one line code fixes without an
	  issue and demonstration will not be accepted.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.   one line code fixes without tests will not be accepted.
- [ ] A new feature implementation
	- please include the issue number, and create an issue if none exists, which must
	  include a complete example of how the feature would look.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.

**Have a nice day!**

Closes: #5166
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5166
Pull-request-sha: 04a7394f71298322188f0861b4dfe93e5485839d

Change-Id: Ib90a59fac929661a18748c6e44966fb87e3978c6

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