Finding the average of a list

Question

I have to find the average of a list in Python. This is my code so far

from functools import reduce  l = [15, 18, 2, 36, 12, 78, 5, 6, 9] print(reduce(lambda x, y: x + y, l)) 

I've got it so it adds together the values in the list, but I don't know how to make it divide into them?

Answer 1

On Python 3.8+, with floats, you can use statistics.fmean as it's faster with floats.

On Python 3.4+, you can use statistics.mean:

l = [15, 18, 2, 36, 12, 78, 5, 6, 9]  import statistics statistics.mean(l)  # = 20.11111111111111 

On older versions of Python you can:

sum(l) / len(l) 

On Python 2, you need to convert len to a float to get float division

sum(l) / float(len(l)) 

There is no need to use functools.reduce as it is much slower.

Answer 2

l = [15, 18, 2, 36, 12, 78, 5, 6, 9] sum(l) / len(l)