trying to make list permutation in python

Question

I need to make a list of all permutations, but the catch is every element comes from a different list. It is supposed to be for a random number of lists.
for example
list1=[1,2,3,4]
list2=[a,b,c,d]
list3=[...]
...
the result should be something like this: [1,a...],[1,b...],[1,c...]..,[2,a..],[2,b]....[4,d..]..

Answer 1

Mihail ,

this does currently not cover your request for a random number of list, but i try to come back later:

from itertools import product # generates the cartesian products of n iterables
list1 = [1,2,3,4]
list2 = ["a","b","c","d"]
print(list(product(list1, list2)))

[EDITED]:
i have done a try, you can find it in the file. there are also some comments included. it may not be perfect for your purpose, but you can see how it can be done:
https://code.sololearn.com/c7ZBA00EOhT5/?ref=app

Answer 2

Using nested list comprehension
list1 = [1,2,3,4]
list2 = ["a","b","c","d"]
list3 = [[i,j] for i in list1 for j in list2]
print(list3)

Answer 3

but i don't know the number of lists beforehand

Answer 4

Lothar is right for as long as there is required a random number of lists.
This comes from the fact that product() xan accept a arbitrary number of lists, so this must be true.
In fact, there can be chosen a random number (i) bellow or equal to a certain number of lists in ready for use and then picking randomly lists for (i) times and then applying product()