Bisect, is it possible to work with descending sorted lists?

Question

How can I use bisect module on lists that are sorted descending? e.g.

import bisect

x = [1.0,2.0,3.0,4.0] # normal, ascending
bisect.insort(x,2.5)  # -->         


        

Answer 1

One approach is to negate the keys. For example,

a = [1,2,3,4]
a.reverse()
def comparator(a):
    return -a
b = [comparator(i) for i in a]
bisect.insort_right(b,comparator(2.5))
a = [comparator(c) for c in b]

Result: [4, 3, 2.5, 2, 1]