The goal of the regex is to catch a (alpha), b (beta), c or rc
(release candidate), so the existing pattern puzzled me. Tests were
OK before and after the change.

This used to be buggy; Filip Gruszczyński contributed tests and a code
patch but the latter is not needed.

(Deleted rather than moved because multilib implementations vary.)

sys.maxunicode is not called and thus does not return anything; it *is*
something.  (I checked the doc quickly to see if it tells that
expression return things but found nothing.)

I also removed markup that would just generate a useless link to the
enclosing section.

Reported and diagnosed by Thomas Kluyver.

Reported and diagnosed by Thomas Kluyver.

if the underlying raw stream is unseekable, even if the seek could be
satisfied using the internal buffer.  Patch by John OConnor.

if the underlying raw stream is unseekable, even if the seek could be
satisfied using the internal buffer.  Patch by John O'Connor.

memory watchdog for timely stats collection.

- bigmemtest is replaced by precisionbigmemtest
- add a poor man's watchdog thread to print memory consumption

- bigmemtest is replaced by precisionbigmemtest
- add a poor man's watchdog thread to print memory consumption

metaclass is registered with copyreg.  Patch by Nicolas M. Thiéry and
Craig Citro.

metaclass is registered with copyreg.  Patch by Nicolas M. Thiéry and
Craig Citro.

Ensure these states with assertions in _PyUnicode_CheckConsistency().

Cleanup also the code.