[Tutor] Code not working advise pls

[tracey jones-Francis]

Hi,

I want to write a function that will calculate and return the sum of the n highest value in a list a. Also, when n is less than 0, the answer should be zero, and if n is greater than the number of elements in the list, all elements should be included in the sum.

In addition i want to write the code in a function with only one line of code in it.
So far I have:-

def sumHighest(a, n):
lambda a, n : sum(a[:n])

This doesn't work but i want to use lambda and the slice in the function.

An appropriate test would be:-

input - sumHighest([1,2,3,4], 2)
output - 7

Where am I going wrong?

Thanks T.