Need help with List of Lists

[pyghorz]

here's another approach:

list_a = [-1, 2, -2, 3, 41, 38, 22, 10, -1, 3]
list_b = [40, 30, 20, 10]

e_len = len(list_a) - len(list_b) + 1

for a_idx in range(e_len):
    elist = []
    b_idx = 0
    for bval in list_b:
        if b_idx == 0:
            print('list{} = '.format(a_idx), end='')
        else:
            print(' + ', end='')
        print('a[{}]*b[{}]'.format(a_idx, b_idx), end='')
        elist.append(list_a[a_idx + b_idx]*bval)
        b_idx += 1
    print(' = {}'.format(sum(elist)))

which results in:

Output:
list0 = a[0]*b[0] + a[0]*b[1] + a[0]*b[2] + a[0]*b[3] = 10
list1 = a[1]*b[0] + a[1]*b[1] + a[1]*b[2] + a[1]*b[3] = 490
list2 = a[2]*b[0] + a[2]*b[1] + a[2]*b[2] + a[2]*b[3] = 1210
list3 = a[3]*b[0] + a[3]*b[1] + a[3]*b[2] + a[3]*b[3] = 2330
list4 = a[4]*b[0] + a[4]*b[1] + a[4]*b[2] + a[4]*b[3] = 3320
list5 = a[5]*b[0] + a[5]*b[1] + a[5]*b[2] + a[5]*b[3] = 2370
list6 = a[6]*b[0] + a[6]*b[1] + a[6]*b[2] + a[6]*b[3] = 1190

thumbsup, i'd love to code it out in C, but python only is allowed. Welldone!

[Larz60+]

I come from a 'C' and 'C++' background, many years, now I'm hooked on Python.

[ljmetzger]

Great job Larz60+. In post #10 Larz60+ output was:

Output:
list0 = a[0]*b[0] + a[0]*b[1] + a[0]*b[2] + a[0]*b[3] = 10
list1 = a[1]*b[0] + a[1]*b[1] + a[1]*b[2] + a[1]*b[3] = 490
list2 = a[2]*b[0] + a[2]*b[1] + a[2]*b[2] + a[2]*b[3] = 1210
list3 = a[3]*b[0] + a[3]*b[1] + a[3]*b[2] + a[3]*b[3] = 2330
list4 = a[4]*b[0] + a[4]*b[1] + a[4]*b[2] + a[4]*b[3] = 3320
list5 = a[5]*b[0] + a[5]*b[1] + a[5]*b[2] + a[5]*b[3] = 2370
list6 = a[6]*b[0] + a[6]*b[1] + a[6]*b[2] + a[6]*b[3] = 1190

I believe the output should be (changed the a indices in output - calculations are identical):

Output:
list0 = a[0]*b[0] + a[1]*b[1] + a[2]*b[2] + a[3]*b[3] = 10
list1 = a[1]*b[0] + a[2]*b[1] + a[3]*b[2] + a[4]*b[3] = 490
list2 = a[2]*b[0] + a[3]*b[1] + a[4]*b[2] + a[5]*b[3] = 1210
list3 = a[3]*b[0] + a[4]*b[1] + a[5]*b[2] + a[6]*b[3] = 2330
list4 = a[4]*b[0] + a[5]*b[1] + a[6]*b[2] + a[7]*b[3] = 3320
list5 = a[5]*b[0] + a[6]*b[1] + a[7]*b[2] + a[8]*b[3] = 2370
list6 = a[6]*b[0] + a[7]*b[1] + a[8]*b[2] + a[9]*b[3] = 1190

Small change in the source code - .format(a_idx [color=#E74C3C]+ b_idx[/color][b][/b], b_idx) was .format(a_idx, b_idx)

list_a = [-1, 2, -2, 3, 41, 38, 22, 10, -1, 3]
list_b = [40, 30, 20, 10]
 
e_len = len(list_a) - len(list_b) + 1
 
for a_idx in range(e_len):
    elist = []
    b_idx = 0
    for bval in list_b:
        if b_idx == 0:
            print('list{} = '.format(a_idx), end='')
        else:
            print(' + ', end='')
        print('a[{}]*b[{}]'.format(a_idx + b_idx, b_idx), end='')
        elist.append(list_a[a_idx + b_idx]*bval)
        b_idx += 1
    print(' = {}'.format(sum(elist)))

Lewis

[Larz60+]

yes, missed that