a break for comprehensions

[Tom Jenkins]

Kevin Lacker wrote:

> Can you do this:
> 
> answer = []
> for x in my_list:
>     if not is_good(x):
>         break
>     answer.append(process(x))
> 
> with a list comprehension somehow? I'm starting to dislike explicit for
> loops just for the purposes of constructing another list from a current one.


do you mean like this?
 >>> def even(x):
... 	return int(divmod(x,2)[1]) == 0
...
 >>> a = [1, 2, 3, 4, 5, 6, 7]
 >>> b = [z for z in a if not even(z)]
 >>> print b
[1, 3, 5, 7]
 >>> c = [z for z in a if even(z)]
 >>> print c
[2, 4, 6]
 >>>

oops sorry just saw that you had process(x) in there... lets try it:

 >>> def process(x):
... 	return str(x)
...
 >>> process(1)
'1'
 >>> c = [process(z) for z in a if even(z)]
 >>> print c
['2', '4', '6']
 >>>

hmmm, seems to work for me (python 2.1)