create a dynamic list of list from a list of list using random

I’m trying to convert a list of list into a list of list with random values with some restrictions.

For example, I have the following list of lists.

a= [[10],[8],[4]] #this list will tell us how many elements/items should be in each list of list. For example in our new list, the first list will have 10 elements/items and so on.

b=[[15],[10],[5]] #this list will be used to determine the maximum number that each element can be.  For example in our new list, since it can only have 10 elements/items we can only reach up to and including number 15. This process is done at random.

I need a new list a to look like the lists below. Each item in the list must be unique (so no repeating values is allowed)

new_list=[[1,2,4,5,8,9,10,11,12,13],[3,4,5,6,7,8,9,10],[1,2,4,5]] # sample output 1
new_list=[[5,6,7,8,9,10,11,12,13,14,15],[1,2,3,4,5,6,7,8],[2,3,4,5]] # sample output 2

This is what I have so far (MWE)

import random

a=[[10],[8],[4]] # list that informs the number of items in each list of list.
b=[[15],[10],[5]] # the restriction list.
new_list=[] #my final list

for values in a:
    new_list.append(values[0])

new_list=[[item] for item in new_list]

print(new_list)

My problem is how do i convert the first list in my new_list into a random list using list b.

I hope this makes sense.

>Solution :

You can use a list comprehension with zip:

new_list = [sorted(random.sample(range(1, j[0]+1), i[0])) for i,j in zip(a,b)]

Example output:

[[1, 2, 4, 7, 8, 10, 11, 12, 13, 14], [1, 3, 4, 5, 7, 8, 9, 10], [1, 2, 3, 4]]

Note that it would be easier to store your input as:

a = [10, 8, 4]
b = [15, 10, 5]

Then you wouldn’t need to slice i/j with [0]