* limit the number of decimals in Polynomial representation

* tests pass

* parenthesize exponential notation in polynomials

* fixed a long line warning

* added polynomial printoptions tests

* polynomial printoptions typo fixed

* made switch to exp notation in polynomial display more natural

* added a test on switching polynomials to exp notation

* fixed linter errors/warnings

* support for nanstr and infstr printoptions in polynomials

* 10^8 threshold for switching to exp notation when displaying polynomials

* merged in PR #21696 fixing issue #21695

* made linter happy

* made some docstring tests pass

* fixed the docs

Co-authored-by: Lev Maximov <lev.maximov@gmail.com>

From my regular expression foo, those are the only 9 case whereas there
are about ~2000 usage that do not have spaces.

While this is ok with docutils/sphinx, it does not seem to be
documented, and that means that other parsers will see that as comments,
leading to for example improper syntax highlighting.

This make it also a tiny bit harder to develop alternative rst parsers.

Additionally removes associated PolyError classes.  These appear to me to be unused outside this file.

Addresses issue #15658 by removing PolyBase class.  Happy to submit alternative PR using getattr approach instead if desired.

Numpydoc format says that the colon need o be omitted if there is no
type, there were also some empty Examples Sections

* TST: refactor sorter tests, use proper ragged array creation syntax

* MAINT: code never hit the exception, but would error when iterating

* MAINT: pytest.mark.parametrize did not add much, removing (from review)

* MAINT: use asanyarray and generalize (from review)

Co-authored-by: Eric Wieser <wieser.eric@gmail.com>

Inheriting from object was necessary for Python 2 compatibility to use
new-style classes. In Python 3, this is unnecessary as there are no
old-style classes.

Dropping the object is more idiomatic Python.