itertools product to generate all possible strings of size 3

问题

Input:

pos_1= 'AVNMHDRW' 
pos_2= 'KNTHDYBW'
pos_3= 'KVNGSDRB'

Trying to find all possible triplets using one item from pos_1, one from pos_2, and one from pos_3

I'm trying to figure out how to use itertools.product(*) but I'm a little confused

Ultimately, I want to create a list (or generator object) of all the different possibilities by taking one from pos_1 then one from pos_2 and then one from pos_3

Example output:

'AKK','ANV','WWB'

pos_1 stands for position one and so on for pos_2 and pos_3.

回答1:

Simple:

itertools.product(pos_1, pos_2, pos_3)

This can be iterated over; if you want a list, just pass it to list.

What exactly is the issue?

Edit: This produces tuples of the items from each source. If you want to join them back into strings, you can do that manually when you iterate:

for a, b, c in itertools.product(pos_1, pos_2, pos_3):
    do_something_with(a + b + c)

or to create the list, you can use a list comprehension:

[a + b + c for a, b, c in itertools.product(pos_1, pos_2, pos_3)]

回答2:

See this answer: In python is ther a concise way to a list comprehension with multiple iterators.

In your case:

triples = [ a+b+c for a in pos_1 for b in pos_2 for c in pos_3 ]

回答3:

You can make such generator using generator expression:

g = (v1+v2+v3  for v1 in pos_1 for v2 in pos_2 for v3 in pos_3)

来源：https://stackoverflow.com/questions/27413493/itertools-product-to-generate-all-possible-strings-of-size-3