Conversion of List of Tuples
Alexander Blinne
news at blinne.net
Tue Dec 4 04:44:32 EST 2012
Am 03.12.2012 20:58, schrieb subhabangalore at gmail.com:
> Dear Group,
>
> I have a tuple of list as,
>
> tup_list=[(1,2), (3,4)]
> Now if I want to covert as a simple list,
>
> list=[1,2,3,4]
>
> how may I do that?
Another approach that has not yet been mentioned here:
>>> a=[(1,2), (3,4)]
>>> b=[]
>>> map(b.extend, a)
[None, None]
>>> b
[1, 2, 3, 4]
map returns [None, None] because extend returns nothing, but now
b==[1,2,3,4].
There are more ways:
>>> from operator import add
>>> reduce(add, a)
(1, 2, 3, 4)
or
>>> reduce(operator.add, (list(t) for t in a))
[1, 2, 3, 4]
I didn't do any performance testing, i guess the first one should be
about as fast es the for-loop approach with .extend() and the other two
might be quite slow. Although this only really matters if you have large
lists.
Greetings
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