Re: Comprehensions

Paul Prescod wrote:

> a = [1,2,3]
> print [ x*2 for x in a]
>
> paul:/tmp pprescod$ ./test.pr
>
> Parse Error: expecting `']''
> --- File: ./test.pr, line: 4, col: 16
> print [ x*2 for x in a]
>                 ^
>
> Uncaught exception:
> Parse Error.

This is a known unfixable problem with functions-as-commands.  It is parsing
it as print[index].  I am pulling functions-as-commands so this problem will
go away.

O>> a = [1,2,3]
[1, 2, 3]
O>> [ x*2 for x in a]
[2, 4, 6]
O>>

> paul:/tmp pprescod$ python ./test.pr
> [2, 4, 6]

How did you get this result?

> Anyhow, generator comprehensions are more modern than list
> comprehensions and you can easily turn a generator comprehension into
> a list comprehension explicitly:
>
> list(x*2 for x in a)
>
> http://www.python.org/dev/doc/devel/whatsnew/node4.html

Ok, I'll put changing list comps into gen comps into the 1.0 list.  I had
never heard of them before.  Are there any other PEPs I should be aware of?

This is technically past the new feature submission deadline but I'll
stretch the rules for you. :-)