how to join 2 python lists by selecting the position randomly but without changing the order-CodePudding

I want to join 2 python lists by selecting index randomly without changing the order,

a=(1,2,3,4,5)
b=(a,b,c,d)

to one of these randomly

final = (a,b,1,c,2,3,4,d,5)
final = (1,a,b,2,c,3,4,d,5)
final = (a,b,c,1,2,d,3,4,5)

etc.

CodePudding user response：

You can use random.shuffle:

from random import shuffle

a = (1, 2, 3, 4, 5)
b = ("a", "b", "c", "d")


out = [iter(a)] * len(a)   [iter(b)] * len(b)
shuffle(out)

out = [next(i) for i in out]
print(out)

Prints (for example):

['a', 'b', 'c', 1, 2, 'd', 3, 4, 5]

The trick here is not to shuffle directly the values but iterators over the two tuples. First we populate the output list with two iterators which are referenced len(a) len(b) times. Shuffle the list and use next() function over the iterators to obtain the real values in order.

CodePudding user response：

I would do something like:

Pseudocode

list_a_index = 0
list_b_index = 0
new_list = []
for i in range(len(list_a)   len(list_b)):
    which_list = chooseRandomList() #get random A or B
    if (which_list == list_a)
        new_list.append(list_a[list_a_index])
        list_a_index  
    #and the same for list_b
    ...

and make sure that you consider the current indices for list_a and list_b while you choose the next random list to pull value from to not go index out of range.