importlib._bootstrap._get_sourcefile().

Thanks to its only use by the C API, it was never properly tested
until now.

Thanks to Neal Norwitz for discovering the bug and Madison May for the patch.

The private attribute was leaking out of importlib and led to at least
one person noticing it. Switch to another hack which won't leak
outside of importlib and is nearly as robust.

(3.3->default) Issue #12990: The "Python Launcher" on OSX could not launch python scripts that have paths that include wide characters.

Issue #12990: The "Python Launcher" on OSX could not launch python scripts that have paths that include wide characters.

(3.3->default) Issue #17860: explicitly mention that std* streams are opened in binary mode by default.

The documentation does mention that the streams are opened in text mode
when univeral_newlines is true, but not that that they are opened in
binary mode when that argument is false and that seems to confuse at
least some users.

The documentation does mention that the streams are opened in text mode
when univeral_newlines is true, but not that that they are opened in
binary mode when that argument is false and that seems to confuse at
least some users.

The division and modulo calculation in deque_item() can be compiled
to fast bitwise operations when the BLOCKLEN is a power of two.

Timing before:

 ~/cpython $ py -m timeit -r7 -s 'from collections import deque' -s 'd=deque(range(10))' 'd[5]'
10000000 loops, best of 7: 0.0627 usec per loop

Timing after:

~/cpython $ py -m timeit -r7 -s 'from collections import deque' -s 'd=deque(range(10))' 'd[5]'
10000000 loops, best of 7: 0.0581 usec per loop

ModuleNotFoundError.

AIX maps the first page of memory at address zero as valid, read-only.  Reading
NULL is not a fault on AIX. This is utilized by IBM compiler optimizations.
One speculatively can indirect through a pointer which may be null without
first testing if null and defer the test before using the value.

AIX maps the first page of memory at address zero as valid, read-only.  Reading
NULL is not a fault on AIX. This is utilized by IBM compiler optimizations.
One speculatively can indirect through a pointer which may be null without
first testing if null and defer the test before using the value.

handler when the function is called twice, so faulthandler.unregister()
restores correctly the original signal handler.