Clarify that on Windows, path must be a directory.
On Unix, path can be a file or a directory.

`os.path.is*()` can return False if the file can't be accessed.
The behaviour is documented in details in `os.path.exists()`.
Link to `os.path.exists()` from `os.path.is*()`.

The code example that demonstrate how to use enum.Flag was missing
the import of enum.auto.

PyMemoryView_FromMemory() created a memoryview referring to
the internal data of the string.  When the string is destroyed
the memoryview become referring to a freed memory.

glibc has removed Sun RPC. Use replacement libtirpc headers and library in
nis module
Signed-off-by: Christian Heimes <christian@python.org>

In lexical analysis reference documentation, the internal link to
the string literal concatenation section was written as`.. _string-catenation:`.
Changed that to `.. _string-concatenation:`.

when serialize into memory buffer with C pickle implementations.

This optimization already is performed when serialize into memory
with Python pickle implementations or into a file with both
implementations.

time.strftime() must use the current LC_CTYPE encoding, not UTF-8
if the UTF-8 mode is enabled.

Add _PyUnicode_DecodeCurrentLocale() function.

Add new fuctions ignoring the UTF-8 mode:

* _Py_DecodeCurrentLocale()
* _Py_EncodeCurrentLocale()
* _PyUnicode_DecodeCurrentLocaleAndSize()
* _PyUnicode_EncodeCurrentLocale()

Modify the readline module to use these functions.

Re-enable test_readline.test_nonascii().

As the remainder was directly parsed as an int, strings like
.600 were parsed as 600 microseconds rather than milliseconds.

Allow building the _uuid extension module on FreeBSD and OpenBSD.

- primary change is to add a new default filter entry for
  'default::DeprecationWarning:__main__'
- secondary change is an internal one to cope with plain
  strings in the warning module's internal filter list
  (this avoids the need to create a compiled regex object
  early on during interpreter startup)
- assorted documentation updates, including many more
  examples of configuring the warnings settings
- additional tests to ensure that both the pure Python and
  the C accelerated warnings modules have the expected
  default configuration

Third party projects may wish to hide their own internal machinery in
order to present more comprehensible tracebacks to end users
(e.g. Jinja2 and Trio both do this).

Previously such projects have had to rely on ctypes to do so:

  https://github.com/pallets/jinja/blob/fe3dadacdf4cf411d0a5b6bbd4d5234697a28af2/jinja2/debug.py#L345
  https://github.com/python-trio/trio/blob/1e86b1aee8c0c759f6f239ae53a05d0d3963c629/trio/_core/_multierror.py#L296

This provides a Python level API for creating and modifying real
Traceback objects, allowing tracebacks to be edited at runtime.

Patch by Nathaniel Smith.

It's more trouble than it's worth, since AppVeyor only checks the HEAD commit of a PR rather than the full diff against the base branch to decide which files changed.

bpo-32499: Add dataclasses.is_dataclass(obj), which returns True if obj is a dataclass or an instance of one. (#5113)