"as" keyword woes

[Steven D'Aprano]

On Wed, 03 Dec 2008 22:02:24 +0000, Martin P. Hellwig wrote:

> Warren DeLano wrote:
>> A bottom line / pragmatic question... hopefully not a FAQ.
>> 
>> Why was it necessary to make "as" a reserved keyword?
> <cut>
> Because it can be used at the import statement to let the imported thing
> be known under another name?
> Something like:
> 
>  >>> import xml.etree.ElementTree as ET

Martin, that doesn't answer the OP's question *at all*. Python 2.5 uses 
"as" in that way, and it is not a keyword. 

>>> import math as MATHS
>>> MATHS
<module 'math' from '/usr/lib/python2.5/lib-dynload/mathmodule.so'>
>>> as = 45
<stdin>:1: Warning: 'as' will become a reserved keyword in Python 2.6
>>> as
<stdin>:1: Warning: 'as' will become a reserved keyword in Python 2.6
45

I'd guess that the change was to simplify the CPython parser. I have no 
idea if it was a tiny change or a significant change, if it made a huge 
difference to Python-dev or a little difference. Perhaps someone on the 
dev team could comment.

While I feel sympathy for the OP, I do have to ask: he's been using 
Python 2.5 for, what, a couple of years now? How many times did he see 
the depreciation warning, and almost certainly the pending depreciation 
warning before that? Python-dev has been talking about making "as" a 
keyword since at least Python 2.3. Why wait until after version 2.6 is 
released before saying anything?



-- 
Steven