Noah wrote:
> I have a list of tuples
> [('a', 1.0), ('b', 2.0), ('c', 3.0)]
> I want to reverse the order of the elements inside the tuples.
> [(1.0,'a'), (2.0, 'b'), (3.0, 'c')]
>
> I know I could do this long-form:
> q = []
> y = [('a', 1.0), ('b', 2.0), ('c', 3.0)]
> for i in y:
> t=list(t)
> t.reverse()
> q.append(tuple(t))
> y = q
>
> But it seems like there should be a clever way to do this with
> a list comprehensions. Problem is I can't see how to apply
> reverse() to each tuple in the list because reverse() a
> list method (not a tuple method) and because it operates
> in-place (does not return a value). This kind of wrecks doing
> it in a list comprehension. What I'd like to say is something like
> this:
> y = [t.reverse() for t in y]
> Even if reverse worked on tuples, it wouldn't work inside a
> list comprehension.
>
> Yours,
> Noah
>
Provided the data remains the same [(a, b), ...]
Python 2.5a2 (r25a2:45740, May 24 2006, 19:50:20)
[GCC 3.3.6] on linux2
>>> x = [('a', 1.0), ('b', 2.0), ('c', 3.0)]
>>> y = [(b, a) for a, b in x]
>>> y
[(1.0, 'a'), (2.0, 'b'), (3.0, 'c')]
Hope this helps,
Adonis
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