For loop in python (Simple)

Question

I have a really really simple question that I struggle with :)

I need to iterate over list of truples in means of lower triangle matrix in python

python code

dataset = #list of truples

for i, left in enumerate(dataset):
  for j, right in enumerate(dataset):
    if j <= i : continue    #fixme there should be a better way
    foo(left,right)

target pseudo code

for( i=0; i<size; i++ )
  for( j=i; j<size; j++ )
    foo(data[i],data[j])

Thank you very very much :)

I'm a "language surfer" and yup many times I use C and Java. So my notion of "pseudo coding" is bias. Thank you for pointing that out :) — Jan Cajthaml
– Jan Cajthaml, Commented Dec 28, 2013 at 8:17

Costa Halicea · Accepted Answer · 2013-12-28 12:12:08Z

5

Based on the pseudo code this should be something like this:

for i in range(0, len(data)):   
  for j in range(i, len(data)):
    foo(data[i],data[j])

also u can do it with one liner:

[foo(data[i],data[j]) for i in range(0, len(data)) for j in range(i, len(data)]

edited Dec 28, 2013 at 12:12

answered Dec 27, 2013 at 18:03

Costa Halicea

1607 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

neuromusic · Accepted Answer · 2016-07-25 20:10:32Z

0

This is a good place to use itertools.

import itertools

for (left,right) in itertools.combinations(data,2):
    foo(left,right)

answered Jul 25, 2016 at 20:10

neuromusic

1145 bronze badges

Collectives™ on Stack Overflow

For loop in python (Simple)

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related