eight 0.1.0

Python 2 to the power of 3. A lightweight porting helper library.

Eight is a Python module that provides a minimalist compatibility layer between Python 3 and 2. Eight lets you write code for Python 3.3+ while providing limited compatibility with Python 2.7 with no code changes. Eight is inspired by six, nine, and python-future, but is more lightweight, easier to use, and unambiguously biased toward Python 3 code: if you remove eight from your code, it will continue to function exactly as it did with eight on Python 3.

To write code for Python 3 that is portable to Python 2, you may also want to read Armin Ronacher’s excellent Python 3 porting guide, as well as the official porting guide.

Writing from eight import * in your code is a no-op in Python 3. In Python 2, it binds a bunch of Python 3 names to their Python 2 equivalents. Also, if you need to import a module that was renamed in Python 3, writing from eight import <module> will do the right thing (equivalent to import <module> on Python 3 and import <old_name> as <module> on Python 2).

Installation

pip install eight

Synopsis

from eight import *
from eight import queue

If you use print, division, non-ASCII literals, or relative imports, you should also add this future import at the top of each source file:

from __future__ import (print_function, division, unicode_literals, absolute_import)

Wrapping stdio

Eight provides wrappers for sys.stdin, sys.stdout, and sys.stderr to make them (and methods that use them) behave like they do on Python 3. Specifically, in Python 3 these streams accept text data, and their .buffer attributes refer to the underlying streams that accept bytes. Eight uses the io module to do the same for you, but subclasses the TextIOWrapper class for sys.stdout and sys.stderr to coerce non-unicode input to unicode on Python 2 (otherwise, because of the Python 2 semantics, things like exception printing cease to work).

To enable stdio wrapping, use the following:

import eight
eight.wrap_stdio()

To revert the effects of this on any of the streams, use the detach method, e.g. sys.stdin = sys.stdin.detach() (but remember to condition this on eight.USING_PYTHON2). See the io module documentation for more information.

Acknowledgments

Python-future for doing a bunch of heavy lifting on backports of Python 3 features.

Links

• Project home page (GitHub)

• Documentation (Read the Docs)

• Package distribution (PyPI)

Bugs

Please report bugs, issues, feature requests, etc. on GitHub.

License

Licensed under the terms of the Apache License, Version 2.0.