getting list without k'th element efficiently and non-destructively

python list copying
user248237 picture user248237 · Jan 26, 2010 · Viewed 20.5k times · Source

I have a list in python and I'd like to iterate through it, and selectively construct a list that contains all the elements except the current k'th element. one way I can do it is this:

l = [('a', 1), ('b', 2), ('c', 3)]
for num, elt in enumerate(l):
  # construct list without current element
  l_without_num = copy.deepcopy(l)
  l_without_num.remove(elt)

but this seems inefficient and inelegant. is there an easy way to do it? note I want to get essentially a slice of the original list that excludes the current element. seems like there should be an easier way to do this.

thank you for your help.

Answer

Chris B. picture Chris B. · Jan 26, 2010 
l = [('a', 1), ('b', 2), ('c', 3)]
k = 1
l_without_num = l[:k] + l[(k + 1):]

Is this what you want?

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