Python: how to find value in list smaller than target

Question

For example I have a non-ordered list of values [10, 20, 50, 200, 100, 300, 250, 150]

I have this code which returns the next greater value:

def GetN         


        

Answer 1

A better and much faster (code and cpu wise) way is to use bisect module which does binary search but for that you will need to sort the list first, here is the sample usage:

import bisect

mylist = [10, 20, 50, 200, 100, 300, 250, 150]
mylist.sort()

index = bisect.bisect(mylist, 55)
print "Greater than target", mylist[index]
print "Smaller than or equal to target", mylist[index-1]

output:

Greater than target 100
Smaller than or equal to target 50

Also you will need to check the returned index, if it is 0 it means you have passed target lower than the lowest