I have two list:
list1 = ["A", "B", "C", "D", "E"]
list2 = ["AA", "BB", "CC", "DD", "EE"]
I want to create every possible combination, as the following:
A-B-C-D-E
A-BB-C-D-E
A-B-C-DD-E...etc.
The rule is that two similar letter (like A-AA, B-BB) can't be in the combination at the same time, and the order is reversible (A-B-C-D-E and B-A-E-C-D is the same in content so i don't need them both)
How can I manage it with itertools?
TL;DR: map('-'.join, product(*zip(list1, list2))).
It's relatively simple to do using itertools, but you have to think through each step carefully.
First, you can zip your two lists together to get a sequence of tuples. Every element in your final result will include exactly one choice from each tuple.
>>> list1 = ["A", "B", "C", "D", "E"]
>>> list2 = ["AA", "BB", "CC", "DD", "EE"]
>>> list(zip(list1, list2))
[('A', 'AA'), ('B', 'BB'), ('C', 'CC'), ('D', 'DD'), ('E', 'EE')]
Next, we'll want the Cartesian product of each of the five tuples. This gives us the 32 different ways of choosing one of A or AA, then one of B or BB, etc. To do that, we use * to unpack the result of zip into five separate arguments for product.
>>> from itertools import product
>>> for x in product(*zip(list1, list2)):
... print(x)
...
('A', 'B', 'C', 'D', 'E')
('A', 'B', 'C', 'D', 'EE')
('A', 'B', 'C', 'DD', 'E')
('A', 'B', 'C', 'DD', 'EE')
('A', 'B', 'CC', 'D', 'E')
('A', 'B', 'CC', 'D', 'EE')
('A', 'B', 'CC', 'DD', 'E')
# etc
Once you have the product, each element of the product is a valid argument to '-'.join to create one of the strings in your desired set:
>>> for x in map('-'.join, product(*zip(list1, list2))):
... print(x)
...
A-B-C-D-E
A-B-C-D-EE
A-B-C-DD-E
A-B-C-DD-EE
A-B-CC-D-E
A-B-CC-D-EE
A-B-CC-DD-E
A-B-CC-DD-EE
A-BB-C-D-E
A-BB-C-D-EE
A-BB-C-DD-E
A-BB-C-DD-EE
A-BB-CC-D-E
A-BB-CC-D-EE
A-BB-CC-DD-E
A-BB-CC-DD-EE
AA-B-C-D-E
AA-B-C-D-EE
AA-B-C-DD-E
AA-B-C-DD-EE
AA-B-CC-D-E
AA-B-CC-D-EE
AA-B-CC-DD-E
AA-B-CC-DD-EE
AA-BB-C-D-E
AA-BB-C-D-EE
AA-BB-C-DD-E
AA-BB-C-DD-EE
AA-BB-CC-D-E
AA-BB-CC-D-EE
AA-BB-CC-DD-E
AA-BB-CC-DD-EE
aandbof length ofN, to createNlists of lengthN, such that theith list is a copy of lista, but with theith entry replaced with theith entry of listb? Is the omission ofAA-B-C-D-EandA-B-CC-D-Eintentional?A-BB-CC-D-Ebe in the output? Your sample output makes me assume that at most only one item of two character list is allowed for a given item.