reviewers:  these docs publish periodically at:
https://docs.sqlalchemy.org/en/gerrit/4042/orm/queryguide/index.html

See the "last generated" timestamp near the bottom of the
page to ensure the latest version is up

Change includes some other adjustments:

* small typing fixes for end-user benefit
* removal of a bunch of old examples for patterns that nobody
  uses or aren't really what we promote now
* modernization of some examples, including inheritance

Change-Id: I9929daab7797be9515f71c888b28af1209e789ff

Change-Id: I8172fdcc3103ff92aa049827728484c8779af6b7

References: #4600
Change-Id: I2a62ddfe00bc562720f0eae700a497495d7a987a

Updated elementtree example to replace the deprecated classical mappings
interface with the current `registry.map_imperatively()` version.

The examples STILL use classical mappings, so the ticket remains open.
This update merely removes the deprecated API in favor of the (temporary?) replacement.

Change-Id: I8ddb86b76d82ac9d87a55edb0225e6b2f6ab4940

* fix: lib/sqlalchemy/sql/lambdas.py

* fix: lib/sqlalchemy/sql/compiler.py

* fix: lib/sqlalchemy/sql/selectable.py

* fix: lib/sqlalchemy/orm/relationships.py

* fix: lib/sqlalchemy/dialects/mssql/base.py

* fix: lib/sql/test_compiler.py

* fix: lib/sqlalchemy/testing/requirements.py

* fix: lib/sqlalchemy/orm/path_registry.py

* fix: lib/sqlalchemy/dialects/postgresql/psycopg2.py

* fix: lib/sqlalchemy/cextension/immutabledict.c

* fix: lib/sqlalchemy/cextension/resultproxy.c

* fix: ./lib/sqlalchemy/dialects/oracle/cx_oracle.py

* fix: examples/versioned_rows/versioned_rows_w_versionid.py

* fix: examples/elementtree/optimized_al.py

* fix: test/orm/test_attribute.py

* fix: test/sql/test_compare.py

* fix: test/sql/test_type_expression.py

* fix: capitalization in test/dialect/mysql/test_compiler.py

* fix: typos in test/dialect/postgresql/test_reflection.py

* fix: typo in tox.ini comment

* fix: typo in /lib/sqlalchemy/orm/decl_api.py

* fix: typo in test/orm/test_update_delete.py

* fix: self-induced typo

* fix: typo in test/orm/test_query.py

* fix: typos in test/dialect/mssql/test_types.py

* fix: typo in test/sql/test_types.py

For a 1.4 / 1.3 merge, rewrite the documentation for
Query.join() to indicate calling forms that are now considered
legacy, including the use of strings in join(), sending a
series of join paths in one call, and using the aliased=True
flag.   update the elementtree examples as well to use aliased()
(they are much simpler to understand this way too) and update
other links.

Also improve docs for aliased() and some other ORM targets
such as PropComparator.

Change-Id: I636e3a9130dc5509e51c2cf60a52f38fcadffbc6
References: #4705

<!-- 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

This is a very useful assertion which prevents unused variables
from being set up allows code to be more readable and sometimes
even more efficient.  test suites seem to be where the most
problems are and there do not seem to be documentation examples
that are using this, or at least the linter is not taking effect
within rst blocks.

Change-Id: I2b3341d8dd14da34879d8425838e66a4b9f8e27d

Partially fixes sqlalchemy/sqlalchemy#4426.

Closes: #4441
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4441
Pull-request-sha: ed90f3b77c2d0f4cc2cd54f40f5af29b489977d2

Change-Id: Ic32e5d8020073da055b12a6aeb61e698a97dc504

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