An implementation of a recursive Binary Search

BinarySearch.py

def BinarySearch(lst, key):
    def Recurse(lst,key,low,high):
        if high < low:
            return -1
        m = (low + high) / 2
        if lst[m] > key:
            return Recurse(lst,key,low,m-1)
        elif lst[m] < key:
            return Recurse(lst,key,m+1,high)
        else:
            return m
    return Recurse(lst,key,0,len(lst)-1)