CODEWITHSUNDEEP
pythonlistsortingfilterfind
kalle
kalle

Reputation: 435

Find index of the first value that is below/above a threshold

I have a list with a series of random floats that go from negative to positive, like:

values = [0.001, 0.05, 0.09, 0.1, 0.4, 0.8, 0.9, 0.95, 0.99]

I wish to filter out the indices that first meet the greater than/less than values that I wish. For example, if I want the first closest value less than 0.1 I would get an index of 2 and if I want the first highest value greater than 0.9 I'd get 7.

I have a find_nearest method that I am using but since this dataset is randomized, this is not ideal.

EDIT: Figured out a solution.

low = next(x[0] for x in enumerate(list(reversed(values))) if x[1] < 0.1)
high = next(x[0] for x in enumerate(values) if x[1] > 0.9)

Upvotes: 2

Views: 3198

Answers (1)

f5r5e5d
f5r5e5d

Reputation: 3706

if the values list gets long you may want the bisect module from the standard lib

bisect_left, bisect_right may serve as the >, < tests

import bisect
values = [0.001, 0.05, 0.09, 0.1, 0.4, 0.8, 0.9, 0.95, 0.99]
bisect.bisect_left(values, .1)
Out[226]: 3

bisect.bisect_right(values, .1)
Out[227]: 4

Upvotes: 2

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