>>> # a Python3 session to demonstrate "list comprehensions"
... 
>>> alist = [ i*i for i in range(10) ]
>>> alist
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
>>> alist2 = [ num for num in alist if num%2 == 0 ]
>>> alist2
[0, 4, 16, 36, 64]
>>> atable = [ [ num1 * num2 for num1 in alist ] for num2 in alist2 ]
>>> atable
[[0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 4, 16, 36, 64, 100, 144, 196, 256, 324], [0, 16, 64, 144, 256, 400, 576, 784, 1024, 1296], [0, 36, 144, 324, 576, 900, 1296, 1764, 2304, 2916], [0, 64, 256, 576, 1024, 1600, 2304, 3136, 4096, 5184]]
>>> # Note: pprint stands for "pretty print"
... 
>>> from pprint import pprint
>>> pprint(atable)
[[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
 [0, 4, 16, 36, 64, 100, 144, 196, 256, 324],
 [0, 16, 64, 144, 256, 400, 576, 784, 1024, 1296],
 [0, 36, 144, 324, 576, 900, 1296, 1764, 2304, 2916],
 [0, 64, 256, 576, 1024, 1600, 2304, 3136, 4096, 5184]]
>>> colsums = [ sum( [atable[i][j] for i in range(len(atable))] )
...             for j in range(len(atable[0])) ]
>>> colsums
[0, 120, 480, 1080, 1920, 3000, 4320, 5880, 7680, 9720]
>>> exit()