"description": "Refactors valid 3.x syntax into valid 2.x syntax, if a syntactical conversion is possible\nDownload\n========\nRelease for 2.7 and 3.x (last version I tested was 3.4.3): https://pypi.python.org/pypi/3to2\nAbstract\n========\nlib3to2 is a set of fixers that are intended to backport code written for\nPython version 3.x into Python version 2.x. The final target 2.x version is\nthe latest version of the 2.7 branch, as that is the last release in the Python\n2.x branch. Some attempts have been made, however, to make code compatible as\nmuch as possible with versions of Python back to 2.5, and bug reports are still\nwelcome for Python features only present in 2.6+ that are not addressed by\nlib3to2.\nThis project came about as a Google Summer of Code (TM) project in 2009.\nStatus\n======\nBecause of the nature of the subject matter, 3to2 is not perfect, so check all\noutput manually. 3to2 does the bulk of the work, but there is code that simply\ncannot be converted into a Python 2 equivalent for one reason or another.\n3to2 will either produce working Python 2 code or warn about why it did not.\nAny other behavior is a bug and should be reported.\nlib3to2's fixers are somewhat well-tested individually, but there is no testing\nthat is done on interactions between multiple fixers, so most of the bugs in\nthe future will likely be found there.\nIntention\n=========\nlib3to2 is intended to be a tool in the process of developing code that is\nbackwards-compatible between Python 3 and Python 2. It is not intended to be a\ncomplete solution for directly backporting Python 3 code, though it can often\nbe used for this purpose without issue. Sufficiently large packages should be\ndeveloped with lib3to2 used throughout the process to avoid backwards-\nincompatible code from becoming too embedded.\nThere are some features of Python 3 that have no equivalent in Python 2, and\nthough lib3to2 tries to fix as many of these as it can, some features are\nbeyond its grasp. This is especially true of features not readily detectable\nby their syntax alone and extremely subtle features, so make sure that code\nusing lib3to2 is thoroughly tested.\nRepository\n==========\nlib3to2 resides at http://bitbucket.org/amentajo/lib3to2, where the bug tracker\ncan be found at http://bitbucket.org/amentajo/lib3to2/issues\nUsage\n=====\nRun \"./3to2\"to convert stdin (\"-\"), files or directories given as\narguments. By default, the tool outputs a unified diff-formatted patch on\nstandard output and a \"what was changed\"summary on standard error, but the\n\"-w\"option can be given to write back converted files, creating\n\".bak\"-named backup files.\nIf you are root, you can also install with \"./setup.py build\"and\n\"./setup.py install\"(\"make install\"does this for you).\nThis branch of 3to2 must be run with Python 3.\nTo install locally (used for running tests as a non-privileged user), the\nscripts assume you are using python3.1. Modify accordingly if you are not.\nRelationship with lib2to3\n=========================\nSome of the fixers for lib3to2 are directly copy-pasted from their 2to3\nequivalent, with the element of PATTERN and the corresponding transformation\nswitched places. Most fixers written for this program with a corresponding\n2to3 fixer started from a clone of the 2to3 fixer, then modifying that fixer to\nwork in reverse. I do not claim original authorship of these fixers, but I do\nclaim that they will work for 3to2, independent of how they work for 2to3.\nIn addition, this program depends on lib2to3 to implement fixers, test cases,\nrefactoring, and grammar. Some portions of lib2to3 were modified to be more\ngeneric to support lib3to2's calls.\nYou should use the latest version of lib2to3 from the Python sandbox rather\nthan the version (if any) that comes with Python. As a convenience,\n\"two2three\"from the Python Package Index is a recent enough version of lib2to3\nrenamed to avoid conflicts. To use this package, replace all usage of\n\"lib2to3\"with \"two2three\"within the 3to2 source files after installing\n\"two2three\"from the PyPI. Depending on the developer's mood, a version of\n3to2 may be provided with this change already made.",
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