Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #8103 > unrolled thread

Better way to iterate over indices?

Back to article view | Back to comp.lang.python

Contents

  Better way to iterate over indices? Billy Mays <noway@nohow.com> - 2011-06-21 14:05 -0400
    Re: Better way to iterate over indices? Ian Kelly <ian.g.kelly@gmail.com> - 2011-06-21 12:15 -0600
    Re: Better way to iterate over indices? Noah Hall <enalicho@gmail.com> - 2011-06-21 19:19 +0100
    Re: Better way to iterate over indices? Benjamin Kaplan <benjamin.kaplan@case.edu> - 2011-06-21 11:20 -0700
    Re: Better way to iterate over indices? Ethan Furman <ethan@stoneleaf.us> - 2011-06-21 11:35 -0700

#8103 — Better way to iterate over indices?

I have always found that iterating over the indices of a list/tuple is 
not very clean:

for i in range(len(myList)):
     doStuff(i, myList[i])




I know I could use enumerate:

for i, v in enumerate(myList):
     doStuff(i, myList[i])

...but that stiff seems clunky.

Are there any better ways to iterate over the indices of a list /tuple?

--Bill

[toc] | [next] | [standalone]

#8105

On Tue, Jun 21, 2011 at 12:05 PM, Billy Mays <noway@nohow.com> wrote:
> I know I could use enumerate:
>
> for i, v in enumerate(myList):
>    doStuff(i, myList[i])
>
> ...but that stiff seems clunky.

Why not:

for i, v in enumerate(myList):
    doStuff(i, v)

[toc] | [prev] | [next] | [standalone]

#8107

On Tue, Jun 21, 2011 at 7:05 PM, Billy Mays <noway@nohow.com> wrote:
> I have always found that iterating over the indices of a list/tuple is not
> very clean:
>
> for i in range(len(myList)):
>    doStuff(i, myList[i])

> I know I could use enumerate:
>
> for i, v in enumerate(myList):
>    doStuff(i, myList[i])
>
> ...but that stiff seems clunky.

You're not using it properly. Think about it. You're giving two names
- i and v. You've forgotten about v -

>>> for i, v in enumerate('fish'):
...     print i, v
...
0 f
1 i
2 s
3 h


HTH.

[toc] | [prev] | [next] | [standalone]

#8108

On Tue, Jun 21, 2011 at 11:05 AM, Billy Mays <noway@nohow.com> wrote:
> I have always found that iterating over the indices of a list/tuple is not
> very clean:
>
> for i in range(len(myList)):
>    doStuff(i, myList[i])
>
>
>
>
> I know I could use enumerate:
>
> for i, v in enumerate(myList):
>    doStuff(i, myList[i])
>
> ...but that stiff seems clunky.

Why does enumerate seem clunky, other than the fact that you should
probably have
    doStuff(i,v)
instead of myList[i] in there? It's a bit more awkward than C's
syntax, but since the typical use case is just iteration anyway, it's
not a huge deal for those few cases where you actually need the
indices.

>
> Are there any better ways to iterate over the indices of a list /tuple?
>
> --Bill
> --
> http://mail.python.org/mailman/listinfo/python-list
>

[toc] | [prev] | [next] | [standalone]

#8109

Billy Mays wrote:
> I have always found that iterating over the indices of a list/tuple is 
> not very clean:
> 
> for i in range(len(myList)):
>     doStuff(i, myList[i])

Definitely not beautiful.  ;)

> I know I could use enumerate:
> 
> for i, v in enumerate(myList):
>     doStuff(i, myList[i])

If you actually need the index, then this is the way to do it.  Note 
that in most cases, you don't need the index and can iterate directly:

for v in myList:
     doStuff(v)

 From your sample code (assuming you don't need i) this does the same thing.

~Ethan~

[toc] | [prev] | [standalone]

Back to top | Article view | comp.lang.python

csiph-web