Iterating two arrays at once

[mathieu]

Hi there,

just trying to figure out how to iterate over two array without
computing the len of the array:

A = [1,2,3]
B = [4,5,6]
for a,b in A,B: # does not work !
print a,b

It should print:

1,4
2,5
3,6

Thanks !

[Bruno Desthuilliers]

Re: Iterating two arrays at once

mathieu a écrit :

Hi there,
>
just trying to figure out how to iterate over two array without
computing the len of the array:
>
A = [1,2,3]
B = [4,5,6]
for a,b in A,B: # does not work !
print a,b
>
It should print:
>
1,4
2,5
3,6

for a, b in zip(A, B):
print a, b

or, using itertools (which might be a good idea if your lists are a bit
huge):

from itertools import izip
for a, b in izip(A, B):
print a, b

[Matthias =?iso-8859-1?q?Bl=E4sing?=]

Re: Iterating two arrays at once

Am Fri, 29 Aug 2008 03:35:51 -0700 schrieb mathieu:>

A = [1,2,3]
B = [4,5,6]
for a,b in A,B: # does not work !
print a,b
>
It should print:
>
1,4
2,5
3,6

Hey,

zip is your friend:

for a,b in zip(A,B):
print a,b

does what you want. If you deal with big lists, you can use izip from
itertools, which returns a generator.

from itertools import izip
for a,b in izip(A,B):
print a,b

HTH

Matthias

[mathieu]

Re: Iterating two arrays at once

On Aug 29, 12:46 pm, Matthias Bläsing <matthias.blaes ...@rwth-
aachen.dewrote:

Am Fri, 29 Aug 2008 03:35:51 -0700 schrieb mathieu:>
>

A = [1,2,3]
B = [4,5,6]
for a,b in A,B: # does not work !
print a,b

>

It should print:

>

1,4
2,5
3,6

>
Hey,
>
zip is your friend:
>
for a,b in zip(A,B):
print a,b
>
does what you want. If you deal with big lists, you can use izip from
itertools, which returns a generator.
>
from itertools import izip
for a,b in izip(A,B):
print a,b

Thanks all !

[Bruno Desthuilliers]

Re: Iterating two arrays at once

mathieu a écrit :
(snip solution)

Thanks all !

FWIW, this has been discussed here *very* recently (a couple hours ago).
Look for a thread named "iterating over two arrays in parallel?", and
pay special attention to Terry Reedy's answer.