Question : merge windows based on condition

Hi,

Let us say i have the following class:

class window(object):
      """docstring for window"""
      def init(self, start, end, score):
            self.start = start
            self.end = end
            self.score = score

And i have a list of objects called windowslist.

I want to create a new list called mergelist where i would merge two windows if their distance, DistanceBetweenConsecutiveWindows = window[i+1].start - window[i].end, is less or equal than 500.

So let us take the following example,
windowslist = [[start = 131544272, end = 131544766, score = 4.4849999999999994], 1st win
[131826840, 131827334, 2.5350000000000001], 2nd win
[131827372, 131827866, 2.3050000000000002], 3rd win
[132027024, 132027518, 2.2050000000000001]] 4th window

In this case I should merge the second and the third windows in window list because their distance is less or equal than 500, d2ndand3rd = 131827372 - 131827334 = 38....

Merging two windows is given by the function merge:
def merge(w1, w2):
      """docstring for merge"""
      return window(w1.start, w2.end, numpy.maximum(float(w1.score),float(w2.score)))

Can you suggest a code to solve my problem for the most general case possible?

Answer : merge windows based on condition

Something like that:

                       
         
           
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             from operator import itemgetter
 
def needmerge(wlist):
  wstart = iter(sorted(enumerate(w.start for w in wlist), key=itemgetter(1)))
  wend = iter(sorted(enumerate(w.end for w in wlist), key=itemgetter(1)))
  merge = []
  s = wstart.next()
  e = wend.next()
  try:
    while True:
      if e[1]-s[1] <= 500:
        if s[0] != e[0]: merge.append((s[0], e[0]))
        e = wend.next()
      else:
        s = wstart.next()
        while s[1] > e[1]: e = wend.next()
  except StopIteration:
    pass
  return merge
 
def domerge(windowlist):
  mlist = needmerge(windowlist)
  if not mlist:
    return windowlist
  merged = set([x[0] for x in mlist]
             + [x[1] for x in mlist])
  mergelist = [w[1] for w in enumerate(windowlist) if w[0] not in merged]
  for m in mlist:
    mergelist.append(merge(*m))
  return mergelist
 
def merge:
  # as you described
           
         

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