The backport of ensurepip to 2.7.9 allows pip to optionally be installed
or upgraded using the bundled pip provided by the new ensurepip module.
The option can be specified persistently using the configure option:

    ./configure --with-ensurepip[=upgrade|install|no]

It can also be overridden on either the "install" or "altinstall" targets:

    make [alt]install ENSUREPIP=[upgrade|install|no]

For Python 2, the default option is "no" (do not install pip).

Warn against the use of leaking macro PyObject_REPR().

Patch by Roumen Petrov.

Fixed an error in _PySys_GetSizeOf declaration.

* Backports ensurepip to the 2.7 branch
* Backports some of the improved documentation to the 2.7 branch.
* Adds a private backport of the 3.x mock library as test._mock_backport
  to enable saner testing of ensurepip.

Key Differences from 3.x:

* Ensurepip does not have any Makefile integration, specifically
  it is not ran by default in the Makefile.
* There is no venv module in 2.7, so downstream distributors can
  completely disable ensurepip, ideally with a message redirecting
  to the correct way to install pip.
* To match the ``python`` command in 2.7, ensurepip will install
  the unversioned ``pip`` command as well.
* No-op and hide --default-pip and add --no-default-pip to restore
  the 3.x behavor on 2.7.

different lowercase are now matched in case-insensitive regular expressions.

platforms.

(issue #814253).

work in lookbehind assertions in regular expressions.

Based on patch by Aivars Kalvāns.

Issue #20160: broken ctypes calling convention on MSVC / 64-bit Windows (large structs). Patch by mattip

Patch by Tim Graham.

#22751: fix test___all__ warning about modified environment in the tests.  Patch by Michael Cetrulo.

When running tests in subprocesses with the regrtest -j option, a bug
in Cocoa Tk can result in a Tcl segfault.  Avoid the problem by forcing
Tk to fully initialize as an OS X gui process before destroying the
Tcl instance and creating another. (Original patch by Serhiy Storchaka)