How to compare multiple lists for numerical closeness two at a time?

Question

Say I have 4 lists:

A = [1.1, 1.4, 2.1, 2.4]
B = [1.3, 6.5, -1.0, 2.3]
C = [0.5, -1.0, -1.1, 2.0]
D = [1.5, 6.3, 2.2, 3.0]

How do I 1)compare the lists eg A,B B,C C,D A,C so on and 2)return true if the elements are +/-0.2 ?

Example output: (Or any other way to represent the data)
A,B [true, false, false, true]
B,C [false, false, true, false]

My thoughts are to append the lists have a for loop to iterate through all.

A.append(B)
A.append(C)
.
.

But then I'm stuck since if I do

for x in A:
    for y in A[x]:
        if A[x][y] - A[x+1][y] <= 0.2
            if A[x+1][y] - A[x][y] <= 0.2

Obviously it doesn't work. Are there ways to iterate through the lists without duplicates and compare at the same time?

Thanks in advance

Answer 1

Update:

OK, now I think I understand both questions you're asking:

from itertools import combinations

A = [1.1, 1.4, 2.1, 2.4]
B = [1.3, 6.5, -1.0, 2.3]
C = [0.5, -1.0, -1.1, 2.0]
D = [1.5, 6.3, 2.2, 3.0]
lists = {'A': A, 'B': B, 'C': C, 'D': D}
tol = 0.2

def compare_lists(a, b, tol):
    return [abs(elem1-elem2) <= tol for elem1, elem2 in zip(a, b)]  # Might want '<' instead

for name1, name2 in combinations(lists.keys(), 2):
    a, b = lists[name1], lists[name2]
    print('{}, {} {}'.format(name1, name2, compare_lists(a, b, tol)))

Output:

A, B [True, False, False, True]
A, C [False, False, False, False]
A, D [False, False, True, False]
B, C [False, False, True, False]
B, D [True, False, False, False]
C, D [False, False, False, False]

Update 2:

To answer your follow up question, if the lists are actually members of a list-of-lists, you could similarly do something like this:

# An alternative for when the lists are nested inside another list

from itertools import combinations

lists = [
    [1.1, 1.4, 2.1, 2.4],
    [1.3, 6.5, -1.0, 2.3],
    [0.5, -1.0, -1.1, 2.0],
    [1.5, 6.3, 2.2, 3.0]
]
tol = 0.2

def compare_lists(a, b, tol):  # unchanged
    return [abs(elem1-elem2) <= tol for elem1, elem2 in zip(a, b)]  # Might want '<' instead

for i, j in combinations(range(len(lists)), 2):  # all combinations of pairs of indices
    a, b = lists[i], lists[j]
    print('{}[{}], [{}] {}'.format('lists', i, j, compare_lists(a, b, tol)))

Output:

lists[0], [1] [True, False, False, True]
lists[0], [2] [False, False, False, False]
lists[0], [3] [False, False, True, False]
lists[1], [2] [False, False, True, False]
lists[1], [3] [True, False, False, False]
lists[2], [3] [False, False, False, False]