How to merge lists into a list of tuples?

Question

What is the Pythonic approach to achieve the following?

# Original lists:

list_a = [1, 2, 3, 4]
list_b = [5, 6, 7, 8]

# List of tuples from \'list_a\' and          


        

Answer 1

In Python 2:

>>> list_a = [1, 2, 3, 4]
>>> list_b = [5, 6, 7, 8]
>>> zip(list_a, list_b)
[(1, 5), (2, 6), (3, 7), (4, 8)]

In Python 3:

>>> list_a = [1, 2, 3, 4]
>>> list_b = [5, 6, 7, 8]
>>> list(zip(list_a, list_b))
[(1, 5), (2, 6), (3, 7), (4, 8)]

Answer 2

The output which you showed in problem statement is not the tuple but list

list_c = [(1,5), (2,6), (3,7), (4,8)]

check for

type(list_c)

considering you want the result as tuple out of list_a and list_b, do

tuple(zip(list_a,list_b)) 

Answer 3

One alternative without using zip:

list_c = [(p1, p2) for idx1, p1 in enumerate(list_a) for idx2, p2 in enumerate(list_b) if idx1==idx2]

In case one wants to get not only tuples 1st with 1st, 2nd with 2nd... but all possible combinations of the 2 lists, that would be done with

list_d = [(p1, p2) for p1 in list_a for p2 in list_b]

Answer 4

You can use map lambda

a = [2,3,4]
b = [5,6,7]
c = map(lambda x,y:(x,y),a,b)

This will also work if there lengths of original lists do not match

Answer 5

In python 3.0 zip returns a zip object. You can get a list out of it by calling list(zip(a, b)).

Answer 6

I am not sure if this a pythonic way or not but this seems simple if both lists have the same number of elements :

list_a = [1, 2, 3, 4]

list_b = [5, 6, 7, 8]

list_c=[(list_a[i],list_b[i]) for i in range(0,len(list_a))]