when applicable.

on OS-X. Patch by Jeff Ramnani.

This has come up often enough now on the tracker that it deserves a FAQ entry.

* Describe compress() and accumulate()
* Add a subsection on combinatoric functions.
* Add a forward link to skip the theoretical discussion in the first section.
* Clarify what filterfalse() is the opposite of.
* Remove the old outline and some notes at the end.
* Various small edits.

initial patch by Trent Nelson.

is imported. Instead, ElementTree.parse can look for a special internal method
defined by the accelerator.

This is useful when mucking with import_fresh_module to either force or block
importing of the _elementtree accelerator. These tests in place provide an
immediate indication whether the accelerator was actually imported and overrode
the classes it should have.

Renaming to _Element_Py for clarity and moving it to a more logical location.
_ElementInterface OTOH is unused and is therefore removed.

Close #17988

Also clean up some code around this

Optimize base64.b32encode() and base64.b32decode() (speed up to 3x).

Based on report and patch by Aaron Oakley.

Based on report and patch by Aaron Oakley.