I recently discovered that assignment expressions exist. And I wanted to refactor some of my code to make use of them. Most of the places I wanted to use it were relatively straightforward to convert.
However, I'm not sure of the syntax to use for this particular function. Is there a way I could replace my usage of functools.reduce with assignment expressions?
from functools import reduce
def get_average(xs):
"""
This function takes in a list of nx3 lists and returns the average
along each column, returning a 3 length list.
"""
return [
x / len(xs)
for x in reduce(
lambda acc, x: [sum(z) for z in zip(acc, x)],
xs,
[0, 0, 0])]
It's not straightforward to me how to use the result of an assignment expression as an expression directly. Is there a nice and pythonic way to do this?
You don't need assignment expressions here, see this simple list comprehension:
[sum(i)/len(i) for i in zip(*l)]
example:
# input
l = [[1,2,3], [4,5,6]]
# output
[2.5, 3.5, 4.5]