which python version need from __future__ import with_statement ?

Question

Currently i'm using python 2.6.5, I didn't use from __ future __ import with_statement,it can use with statement all right. I want to know in which version we need use from __ future __ import with_statement,which not?

Answer 1

You only need it in Python 2.5. Older versions (<= 2.4) don't support it and newer versions (>= 2.6) have it enabled by default.

So if you want to support Python >= 2.5, you can simply put the from __future__ import with_statement at the beginning. For newer versions, it will simply be ignored.

Answer 2

From the doc:

New in version 2.5.

Answer 3

__future__ features are self-documenting. Try this:

>>> from __future__ import with_statement
>>> with_statement.getOptionalRelease()
(2, 5, 0, 'alpha', 1)
>>> with_statement.getMandatoryRelease()
(2, 6, 0, 'alpha', 0)

These respectively indicate the first release supporting from __future__ import with_statement and the first release to support it without using from __future__.

Also, read this:

>>> import __future__
>>> help(__future__)