returns the max product of two items for all adjacent items in the list

adjacent_product.py

# the long way 
def main(a, l):
    for i in a:
        if a.index(i) < a.index(a[-1]):
            n = i * a[a.index(i) + 1]
            l.append(n)
    print(max(l))
    return max(l)

if __name__ == '__main__':
    main([2,3,4,-5,6,-4], list())
    
# pythonic list comprehension
def inputArray(a):
    return max([i * a[a.index(i) + 1] for i in a if a.index(i) < a.index(a[-1])])
inputArray([2,3,4,-5,6,-4])