How to join two lists like this in python

Question

I've these two lists a = [1, 2, 3] and another b = [4, 2, 1]

I want this outcome by join these list like this (items in a with every item of b) :

(1, 4) (1, 2) (1, 1)
(2, 4) (2, 2) (2, 1)
(3, 4) (3, 2) (3, 1)

You could use a nested loop. This seems like homework. What have you tried? Where are you stuck? — John Coleman, Jan 20 '21 at 16:08
[Duplicate](https://google.com/search?q=site%3Astackoverflow.com+python+tuples+cartesian+product+two+arrays) of [Get the cartesian product of a series of lists?](https://stackoverflow.com/q/533905/4642212). — Sebastian Simon, Jan 20 '21 at 16:09

Filippo Vitale · Answer 1 · 2021-01-20T16:11:30.693

1

For generating the cartesian product:

cart_prod = [(i, j) for i in a for j in b]

EDIT the question changed

>>> for i in a:
...   print([(i, j) for j in b])
...
[(1, 4), (1, 2), (1, 1)]
[(2, 4), (2, 2), (2, 1)]
[(3, 4), (3, 2), (3, 1)]

edited Jan 20 '21 at 16:11

answered Jan 20 '21 at 16:08

Filippo Vitale

2

As someone with enough rep to cast close votes, why answer this basic question rather than VTC as a duplicate of the many similar questions asked before? – Sebastian Simon Jan 20 '21 at 16:11
You are right Sebastian, this could be the first Python answer I am giving – Filippo Vitale Jan 20 '21 at 16:12

1 Answers1