calculate average sum from second value of each tuple in python

Question

I used this here to sum the second value of each tuple in a list: https://stackoverflow.com/a/12218119/9195816

sum(n for _, n in structure) works fine. But i dont need the sum, i only need the average. So something like sum(n for _, n in structure) \ total_amount_of_values. But of course, this won't work:

TypeError: unsupported operand type(s) for /: 'float' and 'list'

My list looks i.e. like this: [1000, 900.84, 500, 1240.11]

The error is stating you are trying to divide a float and a list, can you provide the contents for the variables you are dividing? — MooingRawr, Jan 12 '18 at 14:27
how does your tuple look like? Also, *"But i dont need the sum, i also need the average"* this is not clear. Do you or do you **not** need the sum? — Ma0, Jan 12 '18 at 14:28

score 1 · Accepted Answer · answered Jan 12 '18 at 14:33

n = [1000, 900.84, 500, 1240.11]
average = sum(n)/len(n)

This will give you the average of the list n

But it sounds like your list looks more like this

n = [(a,b), (c,d), ...]

and you want

b + d + ... / len(n)

If this is the case, then you can do this like so

average = sum(map(lambda x: x[1], n)) / len(n)

calculate average sum from second value of each tuple in python

1 Answers1