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From: Oltmans on 8 May 2010 16:41
Hi, I've a list that looks like following

a = [ [1,2,3,4], [5,6,7,8] ]

Currently, I'm iterating through it like

for i in [k for k in a]:
for a in i:
print a

but I was wondering if there is a shorter, more elegant way to do it?
From: superpollo on 8 May 2010 16:53
Oltmans ha scritto:
> Hi, I've a list that looks like following
>
> a = [ [1,2,3,4], [5,6,7,8] ]
>
> Currently, I'm iterating through it like
>
> for i in [k for k in a]:
> for a in i:

i think you used te a identifier for two meanings...

> print a
>
> but I was wondering if there is a shorter, more elegant way to do it?


add = lambda a,b: a+b
for i in reduce(add,a):
print i
From: Chris Rebert on 8 May 2010 16:55
On Sat, May 8, 2010 at 1:41 PM, Oltmans <rolf.oltmans(a)gmail.com> wrote:
> Hi, I've a list that looks like following
>
> a = [ [1,2,3,4], [5,6,7,8] ]
>
> Currently, I'm iterating through it like
>
> for i in [k for k in a]:
>        for a in i:
>                print a
>
> but I was wondering if there is a shorter, more elegant way to do it?

Just use a different variable name besides `a` in the nested loop so
you don't have to make the copy of `a`. I arbitrarily chose `b`:

for i in a:
for b in i:
print b

Cheers,
Chris
--
http://blog.rebertia.com
From: superpollo on 8 May 2010 16:56
superpollo ha scritto:
> Oltmans ha scritto:
>> Hi, I've a list that looks like following
>>
>> a = [ [1,2,3,4], [5,6,7,8] ]
>>
>> Currently, I'm iterating through it like
>>
>> for i in [k for k in a]:
>> for a in i:
>
> i think you used te a identifier for two meanings...
>
>> print a
>>
>> but I was wondering if there is a shorter, more elegant way to do it?
>
>
> add = lambda a,b: a+b

or:

from operator import add


> for i in reduce(add,a):
> print i
From: Alain Ketterlin on 8 May 2010 16:56
Oltmans <rolf.oltmans(a)gmail.com> writes:

> a = [ [1,2,3,4], [5,6,7,8] ]
>
> Currently, I'm iterating through it like
>
> for i in [k for k in a]:
> for a in i:
> print a

I would prefer:

for i in a:
for v in i:
print v

i.e., not messing with a and avoiding an additional list.

> but I was wondering if there is a shorter, more elegant way to do it?

I can't see any, but if you need to save space, you may use

for v in (e for l in a for e in l):
...

-- Alain.
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