How to store an inner list to an outer list

Question

#Total distance values are stored here
total_dis = []
#Permutation of cooridnates 
perm = permutations(result_List, num_dot)
for i in perm: 
    route = list(i)
    route.append(route[0])
    print(route)
    for (x1, y1), (x2, y2) in zip(route, route[1:]):
        distance_formula = math.sqrt((x2 - x1) ** 2 + (y2 - y1) ** 2)
        print(distance_formula)

I am calculating the distance between the points of each of the generated permutations.

[(5, 0), (4, 5), (2, 9), (5, 0)]
5.0990195135927845
4.47213595499958
9.486832980505138
[(5, 0), (2, 9), (4, 5), (5, 0)]
9.486832980505138
4.47213595499958
5.0990195135927845
[(4, 5), (5, 0), (2, 9), (4, 5)]
5.0990195135927845
9.486832980505138
4.47213595499958
...

I am trying to store the values of distance_formula in lists within the list total_dis. (I figured storing the floats in a list will allow me to find the sums of each list.) Like so:

[[5.0990195135927845, 4.47213595499958, 9.486832980505138],[9.486832980505138, 4.47213595499958, 5.0990195135927845], [5.0990195135927845, 9.486832980505138, 4.47213595499958],[...]]

I am having trouble creating the new lists for the distances between each point of each permutations to be stored.

Answer 1

Just add three lines

#Total distance values are stored here
total_dis = []
#Permutation of cooridnates 
perm = permutations(result_List, num_dot)
for i in perm: 
    route = list(i)
    route.append(route[0])
    print(route)
    dis_list = []                             # <----  Add this line 
    for (x1, y1), (x2, y2) in zip(route, route[1:]):
        distance_formula = math.sqrt((x2 - x1) ** 2 + (y2 - y1) ** 2)
        print(distance_formula)
        dis_list.append(distance_formula)     # <----  Add this line 
    total_dis.append(dis_list)                # <----  Add this line (outside the "distance" loop)

You might even opt to do it as a nested list comprehension, though it might be a lot less readable.

total_dis = [
    [
        math.sqrt((x2 - x1) ** 2 + (y2 - y1) ** 2)
        for (x1, y1), (x2, y2) in zip(
                i + (i[0], )[:-1],
                i + (i[0], )[1:]
            )
    [
    for i in permutations(result_List, num_dot)
]