Check if an object is in a sorted list

Asked Feb 05 '18 at 16:22

Active Feb 05 '18 at 16:26

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What's the easiest way to check weather an object is in a sorted list? I have found bisect, but that only finds the insertion points. Sure this index could then be used to check if the object exists in the list. But is there a easier way?

Something similar to the "in" command? Returning a True/False but for sorted lists?

asked Feb 05 '18 at 16:22

3

Think about it, if `bisect` lets you find the insertion point, how you could check if the value is in the list at that point.. – Martijn Pieters Feb 05 '18 at 16:24
if the index belongs to the list, that is. – Jean-François Fabre Feb 05 '18 at 16:24
So I need to do something like, L[bisect(L,n)-1] == n ? – Feb 05 '18 at 16:52
@Johan: use `bisect_left()`, and you don't have to subtract. You'll have to account for the possibility that the resulting index is 1 higher than the last valid index. So use `idx = bisect_left(L, n)` and then use `idx < len(L) and L[idx] == n`. – Martijn Pieters Feb 05 '18 at 17:02

Check if an object is in a sorted list

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