[Python-Dev] List comprehensions

[M.-A. Lemburg]

Paul Prescod wrote:
> 
> Skip Montanaro wrote:
> >
> >     Paul> [for x: if y(x): for z: (x,y,z)]
> >
> > Agreed, however, your use of colons connotes the following to me
> >
> >     l = []
> >     for x in something:
> >         if y(x):
> >             for z in something_else:
> >                 l.append((x,y,z))
> >     return l
> 
> Yes, that's right. I forgot the "in something" and "in something_else"
> parts but your interpretation was still correct (a fault tolerant
> notation!!).
> 
> [for x in something: if y(x): for z in something_else: (x,y,z)]

Is it really necessary to have all the "code" inside the square
brackets ?

I always thought of list comprehension as a fast way to
just throw together a list, not as a way to "program" the
list contents. IMHO, that should be done using explicit
statements in the way Skip describes above.

I would be completely satisfied with e.g. [0..10], [0..10:2]
and [10..0].

-- 
Marc-Andre Lemburg
______________________________________________________________________
Business:                                      http://www.lemburg.com/
Python Pages:                           http://www.lemburg.com/python/