binary search using python

source code
def binarySearch(alist, item):
        first = 0
        last = len(alist)-1
        found = False
   
        while first<=last and not found:
            midpoint = (first + last)//2
            if alist[midpoint] == item:
                found = True
            else:
                if item < alist[midpoint]:
                    last = midpoint-1
                else:
                    first = midpoint+1
   
        return found
   
    testlist = [0, 1, 2, 8, 13, 17, 19, 32, 42,]
    print(binarySearch(testlist, 3))
    print(binarySearch(testlist, 13))