find closest values between sublists with threshold

Question

I have a function for calculate closest value between sublists. But i need to find only one value for each sublist, considering the threshold. What can i do?

eee=[[22,27,28],[23,18,38]] 
www=[[30],[20]]

xx1=[]
for ee, ww in zip(eee, www):
    for w in ww:
        xx=[]
        for e in ee:
            cc = abs(e - w)
            if -7 <= cc <= 7:
                xx.append(e)
    xx1.append(xx)
print(xx1)

The expected values ​​could be:

[[28],[18]]

Answer 1

Since your www variable is a list of lists rather than a list of integers, each of its sub-lists can potentially hold more than one value even though there is only one value in each sub-list in your example. If there can indeed be more than one value in each sub-list in www, I would suggest that you use itertools.product to produce all the combinations of each item in the corresponding sub-lists of the two lists, and then use the min function with a key function that returns the distance between each pair of values to find the item in each sub-list of eee that's closest to any item in the corresponding sub-list in www:

from itertools import product
from operator import sub
[min(product(e, w), key=lambda p: abs(sub(*p)))[0] for e, w in zip(eee, www)]

This returns:

[28, 18]