sum for sequences?
in [Python]
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From: kj on 24 Mar 2010 11:29 Is there a sequence-oriented equivalent to the sum built-in? E.g.: seq_sum(((1, 2), (5, 6))) --> (1, 2) + (5, 6) --> (1, 2, 5, 6) ? (By "sequence" I'm referring primarily to lists and tuples, and excluding strings, since for these there is ''.join()). TIA! ~K
From: Glazner on 24 Mar 2010 11:39 On Mar 24, 5:29 pm, kj <no.em...(a)please.post> wrote: > Is there a sequence-oriented equivalent to the sum built-in? E.g.: > > seq_sum(((1, 2), (5, 6))) --> (1, 2) + (5, 6) --> (1, 2, 5, 6) > > ? > > (By "sequence" I'm referring primarily to lists and tuples, and > excluding strings, since for these there is ''.join()). > > TIA! > > ~K try itertools.chain
From: Neil Cerutti on 24 Mar 2010 11:42 On 2010-03-24, kj <no.email(a)please.post> wrote: > > > Is there a sequence-oriented equivalent to the sum built-in? E.g.: > > seq_sum(((1, 2), (5, 6))) --> (1, 2) + (5, 6) --> (1, 2, 5, 6) > > ? > > (By "sequence" I'm referring primarily to lists and tuples, and > excluding strings, since for these there is ''.join()). reduce, or functools.reduce in Python 3.1. >>> functools.reduce(operator.add, ((1, 2), (5, 6))) (1, 2, 5, 6) -- Neil Cerutti "It's not fun to build walls. But it's even less fun to live without walls in a world full of zombies." --Greedy Goblin
From: Steve Holden on 24 Mar 2010 11:42 kj wrote: > > Is there a sequence-oriented equivalent to the sum built-in? E.g.: > > seq_sum(((1, 2), (5, 6))) --> (1, 2) + (5, 6) --> (1, 2, 5, 6) > > ? > > (By "sequence" I'm referring primarily to lists and tuples, and > excluding strings, since for these there is ''.join()). > Do you mean you want to flatten a list structure? There have been several discussions about this, which Google will find for you quite easily. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 See PyCon Talks from Atlanta 2010 http://pycon.blip.tv/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS: http://holdenweb.eventbrite.com/
From: Duncan Booth on 24 Mar 2010 12:20
kj <no.email(a)please.post> wrote: > Is there a sequence-oriented equivalent to the sum built-in? E.g.: > > seq_sum(((1, 2), (5, 6))) --> (1, 2) + (5, 6) --> (1, 2, 5, 6) > > ? > Apart from the suggestions for Google for general list flattening, for this specific example you could just use the 'sum' built-in: >>> sum(((1, 2), (5, 6)), ()) (1, 2, 5, 6) Just give it an empty tuple as the starting value. |