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🏷️ NAME

past

🚀 Quick Reference

Use Case	Command	Description
Legacy byte string type	from past.builtins import str as oldstr	Provides Python 2‑like byte string with indexing returning 1‑char strings
Legacy list‑producing range	from past.builtins import range	Returns a list instead of an iterator
Execute a file	from past.builtins import execfile	execfile() resurrected from Python 2
Read from stdin	from past.builtins import raw_input	raw_input() resurrected from Python 2
Reload a module	from past.builtins import reload	Equivalent to imp.reload()
Python 2 xrange	from past.builtins import xrange	Emulates Python 2 xrange
Auto‑translate Py2 module	from past.translation import autotranslate authotranslate('mymodule') import mymodule	Import and run Python 2 code in Python 3

📖 DESCRIPTION

past: compatibility with Python 2 from Python 3

past is a package to aid with Python 2/3 compatibility. Whereas future contains backports of Python 3 constructs to Python 2, past provides implementations of some Python 2 constructs in Python 3 and tools to import and run Python 2 code in Python 3. It is intended to be used sparingly, as a way of running old Python 2 code from Python 3 until the code is ported properly.

Potential uses for libraries:

• as a step in porting a Python 2 codebase to Python 3 (e.g. with the futurize script)
• to provide Python 3 support for previously Python 2‑only libraries with the same APIs as on Python 2 – particularly with regard to 8‑bit strings (the past.builtins.str type).
• to aid in providing minimal‑effort Python 3 support for applications using libraries that do not yet wish to upgrade their code properly to Python 3, or wish to upgrade it gradually to Python 3 style.

Here are some code examples that run identically on Python 3 and 2:

>>> from past.builtins import str as oldstr

>>> philosopher = oldstr(u'孔子'.encode('utf-8'))
>>> # This now behaves like a Py2 byte-string on both Py2 and Py3.
>>> # For example, indexing returns a Python 2-like string object, not
>>> # an integer:
>>> philosopher[0]
'å'
>>> type(philosopher[0])
<past.builtins.oldstr>

>>> # List-producing versions of range, reduce, map, filter
>>> from past.builtins import range, reduce
>>> range(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> reduce(lambda x, y: x+y, [1, 2, 3, 4, 5])
15

>>> # Other functions removed in Python 3 are resurrected ...
>>> from past.builtins import execfile
>>> execfile('myfile.py')

>>> from past.builtins import raw_input
>>> name = raw_input('What is your name? ')
What is your name? [cursor]

>>> from past.builtins import reload
>>> reload(mymodule)   # equivalent to imp.reload(mymodule) in Python 3

>>> from past.builtins import xrange
>>> for i in xrange(10):
...     pass

It also provides import hooks so you can import and use Python 2 modules like this:

$ python3

>>> from past.translation import autotranslate
>>> authotranslate('mypy2module')
>>> import mypy2module

until the authors of the Python 2 modules have upgraded their code. Then, for example:

>>> mypy2module.func_taking_py2_string(oldstr(b'abcd'))

✨ Credits

:Author: Ed Schofield, Jordan M. Adler, et al

:Sponsor: Python Charmers Pty Ltd, Australia: http://pythoncharmers.com

📜 Licensing

Copyright 2013-2019 Python Charmers Pty Ltd, Australia.
The software is distributed under an MIT licence. See LICENSE.txt.

📦 PACKAGE CONTENTS

• 📁 builtins (package)
• 📁 translation (package)
• 📁 types (package)
• 📁 utils (package)

📊 DATA

__copyright__ = 'Copyright 2013-2019 Python Charmers Pty Ltd'

__license__ = 'MIT'

__title__ = 'past'

🔢 VERSION

0.18.2

👤 AUTHOR

Ed Schofield

📁 FILE

/usr/lib/python3/dist-packages/past/__init__.py

🏷️ NAME 🚀 Quick Reference 📖 DESCRIPTION 📦 PACKAGE CONTENTS 📊 DATA 🔢 VERSION 👤 AUTHOR 📁 FILE