Binary search recursive python

Question

im new to data structures and want to ask why is my binary search giving me an error.

I've tried running in the vsc terminal and gives me a syntax error. meanwhile,the problems tab isn't showing giving me any errors. would appreciate the pointers!

def binarysearch(list,value):
    if list == [] or (len(list)==1 and list[0]!= value):
        return False
    else:
        mid = list[len(list)/2]
        if mid == value:
            return True
        elif mid > value:
            return binarysearch(list[:len(list)/2],value)
        else:
            return binarysearch(list[len(list)/2+1:],value)

a =[1,2,3,4,5,6,7,8]
value = 7

if binarysearch(a,value):
    print("found")
else:
    print("none")

Answer 1

The problem is in the lines that you call the recursion, the index to split must be an integer and not a float. Try the following code -

def binarysearch(list,value):
    if list == [] or (len(list)==1 and list[0]!= value):
        return False
    else:
        mid = list[int(len(list)/2)]
        if mid == value:
            return True
        elif mid > value:
            return binarysearch(list[:int(len(list)/2)],value)
        else:
            return binarysearch(list[int(len(list)/2)+1:],value)

a =[1,2,3,4,5,6,7,8]
value = 7

if binarysearch(a,value):
    print("found")
else:
    print("none")