2d numpy.array（）将一个字符串与所有其他字符串进行比较，并对每个字符串重复

Question

Supposed I have an input file with a list of strings (I'm using int's here for cleanliness), eg 1,2,3,4,5,6,...,n

I would like to generate a 2D numpy.array that looks like this:

a = [1,1], [1,2], [1,3], [1,4], ..., [1,n]

And then repeat with each consecutive string, eg

a = [2,1], [2,2], [2,3], [2,4], ..., [2,n], ...[n,n]

How can I go about this?

Answer 1

Check out the itertools library. The product function seems to be what you are after

In [19]: list( product([1, 2, 3, 4, 5], repeat=2) )
Out[19]: 
[(1, 1),
 (1, 2),
 (1, 3),
 (1, 4),
 (1, 5),
 (2, 1),
 (2, 2),
 (2, 3),
 (2, 4),
 (2, 5),
 (3, 1),
 (3, 2),
 (3, 3),
 (3, 4),
 (3, 5),
 (4, 1),
 (4, 2),
 (4, 3),
 (4, 4),
 (4, 5),
 (5, 1),
 (5, 2),
 (5, 3),
 (5, 4),
 (5, 5)]