**************************** What's New in Python 2.7 **************************** :Author: A.M. Kuchling (amk at amk.ca) :Release: |release| :Date: |today| .. $Id$ Rules for maintenance: * Anyone can add text to this document. Do not spend very much time on the wording of your changes, because your text will probably get rewritten to some degree. * The maintainer will go through Misc/NEWS periodically and add changes; it's therefore more important to add your changes to Misc/NEWS than to this file. * This is not a complete list of every single change; completeness is the purpose of Misc/NEWS. Some changes I consider too small or esoteric to include. If such a change is added to the text, I'll just remove it. (This is another reason you shouldn't spend too much time on writing your addition.) * If you want to draw your new text to the attention of the maintainer, add 'XXX' to the beginning of the paragraph or section. * It's OK to just add a fragmentary note about a change. For example: "XXX Describe the transmogrify() function added to the socket module." The maintainer will research the change and write the necessary text. * You can comment out your additions if you like, but it's not necessary (especially when a final release is some months away). * Credit the author of a patch or bugfix. Just the name is sufficient; the e-mail address isn't necessary. * It's helpful to add the bug/patch number in a parenthetical comment. XXX Describe the transmogrify() function added to the socket module. (Contributed by P.Y. Developer; :issue:`12345`.) This saves the maintainer some effort going through the SVN logs when researching a change. This article explains the new features in Python 2.7. No release schedule has been decided yet for 2.7. .. Compare with previous release in 2 - 3 sentences here. add hyperlink when the documentation becomes available online. .. ======================================================================== .. Large, PEP-level features and changes should be described here. .. Should there be a new section here for 3k migration? .. Or perhaps a more general section describing module changes/deprecation? .. ======================================================================== Kristján Valur Jónsson, issue 4293 Py_AddPendingCall is now thread safe. This allows any worker thread to submit notifications to the python main thread. This is particularly useful for asynchronous IO operations. Other Language Changes ====================== Some smaller changes made to the core Python language are: * The :func:`int` and :func:`long` types gained a ``bit_length`` method that returns the number of bits necessary to represent its argument in binary:: >>> n = 37 >>> bin(37) '0b100101' >>> n.bit_length() 6 >>> n = 2**123-1 >>> n.bit_length() 123 >>> (n+1).bit_length() 124 (Contributed by Fredrik Johansson and Victor Stinner; :issue:`3439`.) .. ====================================================================== Optimizations ------------- To be written. .. ====================================================================== New, Improved, and Deprecated Modules ===================================== As in every release, Python's standard library received a number of enhancements and bug fixes. Here's a partial list of the most notable changes, sorted alphabetically by module name. Consult the :file:`Misc/NEWS` file in the source tree for a more complete list of changes, or look through the Subversion logs for all the details. * A new function in the :mod:`subprocess` module, :func:`check_output`, runs a command with a specified set of arguments and returns the command's output as a string if the command runs without error, or raises a :exc:`CalledProcessError` exception otherwise. :: >>> subprocess.check_output(['df', '-h', '.']) 'Filesystem Size Used Avail Capacity Mounted on\n /dev/disk0s2 52G 49G 3.0G 94% /\n' >>> subprocess.check_output(['df', '-h', '/bogus']) ... subprocess.CalledProcessError: Command '['df', '-h', '/bogus']' returned non-zero exit status 1 (Contributed by Gregory P. Smith.) * It is not mandatory anymore to store clear text passwords in the :file:`.pypirc` file when registering and uploading packages to PyPI. As long as the username is present in that file, the :mod:`distutils` package will prompt for the password if not present. (Added by tarek, with the initial contribution of Nathan Van Gheem; :issue:`4394`.) .. ====================================================================== .. whole new modules get described in subsections here .. ====================================================================== Build and C API Changes ======================= Changes to Python's build process and to the C API include: * If you use the :file:`.gdbinit` file provided with Python, the "pyo" macro in the 2.7 version will now work when the thread being debugged doesn't hold the GIL; the macro will now acquire it before printing. (Contributed by haypo XXX; :issue:`3632`.) .. ====================================================================== Port-Specific Changes: Windows ----------------------------------- * The :mod:`msvcrt` module now contains some constants from the :file:`crtassem.h` header file: :data:`CRT_ASSEMBLY_VERSION`, :data:`VC_ASSEMBLY_PUBLICKEYTOKEN`, and :data:`LIBRARIES_ASSEMBLY_NAME_PREFIX`. (Added by Martin von Loewis (XXX check); :issue:`4365`.) .. ====================================================================== Port-Specific Changes: Mac OS X ----------------------------------- .. ====================================================================== Porting to Python 2.7 ===================== This section lists previously described changes and other bugfixes that may require changes to your code: To be written. .. ====================================================================== .. _acks27: Acknowledgements ================ The author would like to thank the following people for offering suggestions, corrections and assistance with various drafts of this article: no one yet.