can we append a list with another list in Python ?

[Joshua Landau]

On 23 October 2012 21:06, Joshua Landau <joshua.landau.ws at gmail.com> wrote:

> On 23 October 2012 21:03, Joshua Landau <joshua.landau.ws at gmail.com>wrote:
>
>> On 23 October 2012 12:07, Jean-Michel Pichavant <jeanmichel at sequans.com>wrote:
>>
>>> ----- Original Message -----
>>>
>>> > Thankyou.. but my problem is different than simply joining 2 lists
>>> > and it is done now :)....
>>>
>>>
>>> A lot of people though you were asking for joining lists, you
>>> description was misleading.
>>>
>>> I'll take a guess: you want to flatten a list of list.
>>> "Nested" list comprehensions can do the trick.
>>>
>>> aList =[[1,5], [2,'a']]
>>> [item for sublist in aList for item in sublist]
>>>
>>> ...
>>> [1, 5, 2, 'a']
>>>
>>> I find it rather difficult to read though.
>>
>>
>> We have a library function for this, in the one-and-only itertools.
>>
>> >>> listoflists = [list(range(x, 2*x)) for x in range(5)]
>>> >>> listoflists
>>> [[], [1], [2, 3], [3, 4, 5], [4, 5, 6, 7]]
>>> >>> from itertools import chain
>>>  >>> list(chain.from_iterable(listoflists))
>>> [1, 2, 3, 3, 4, 5, 4, 5, 6, 7]
>>
>>
>> It does exactly what it says... fast and easy-to-read.
>
>
> Note that I think what he really wanted is to go from
>
> a, b, c = [list(x) for x in (range(10), range(11, 20), range(21, 30))]
>
> to
>
>> list(range(30))
>
>
UNDO! UNDO! UNDO!

I *meant *to say:

Note that I think what he really wanted is to go from

a, b, c = [list(x) for x in (range(10), range(11, 20), range(21, 30))]

to

> [a, b, c]
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