- **Python**
(*http://www.velocityreviews.com/forums/f43-python.html*)

- - **syntax question**
(*http://www.velocityreviews.com/forums/t329601-syntax-question.html*)

syntax questionIf I have a list of touples:
l = [(x1, y1), (x2, y2), ...] Is there a 1 line way to extract and get the sum of each x and y column. I can do it this way with 2 lines of code and iterating through the list twice: sumx = sum([x for x, y in l]) sumy = sum([y for x, y in l]) Is there a 1 liner way to get the sums of both x and y and only iterate thru the list once? Also, is there a way to extract a list of x's and a list of y's from the touple list? 1 line of course. Thanks! AF |

Re: syntax questionAF wrote:
> If I have a list of touples: > > l = [(x1, y1), (x2, y2), ...] > > Is there a 1 line way to extract and get the sum of each x and y > column. I can do it this way with 2 lines of code and iterating > through the list twice: > > sumx = sum([x for x, y in l]) > sumy = sum([y for x, y in l]) > > Is there a 1 liner way to get the sums of both x and y and only > iterate thru the list once? > > Also, is there a way to extract a list of x's and a list of y's from > the touple list? 1 line of course. Use zip: >>> l = ((1, 2), (3, 4), (5, 6)) >>> zip(*l) [(1, 3, 5), (2, 4, 6)] >>> xSum, ySum = map(sum, zip(*l)) >>> xSum 9 >>> ySum 12 -- __ Erik Max Francis && max@alcyone.com && http://www.alcyone.com/max/ / \ San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis \__/ I do this for the love of music / Not for the glitter and gold -- India Arie |

Re: syntax question>>> L=[(1,2),(10,20),(100,200)]
>>> map(None,*L) [(1, 10, 100), (2, 20, 200)] >>> sum(map(None,*L)[0]) 111 "AF" <AnthonyF@Blarg.NET> wrote in message news:c10dc8.0404051323.4594717c@posting.google.com ... | If I have a list of touples: | | l = [(x1, y1), (x2, y2), ...] | | Is there a 1 line way to extract and get the sum of each x and y | column. I can do it this way with 2 lines of code and iterating | through the list twice: | | sumx = sum([x for x, y in l]) | sumy = sum([y for x, y in l]) | | Is there a 1 liner way to get the sums of both x and y and only | iterate thru the list once? | | Also, is there a way to extract a list of x's and a list of y's from | the touple list? 1 line of course. | | Thanks! | | AF |

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