Python | Unpacking tuple of lists

Last Updated : 08 Mar, 2023

Given a tuple of lists, write a Python program to unpack the elements of the lists that are packed inside the given tuple.

Examples:

Input : (['a', 'apple'], ['b', 'ball']) Output : ['a', 'apple', 'b', 'ball']  Input : ([1, 'sam', 75], [2, 'bob', 39], [3, 'Kate', 87]) Output : [1, 'sam', 75, 2, 'bob', 39, 3, 'Kate', 87]

Approach #1 : Using reduce() reduce() is a classic list operation used to apply a particular function passed in its argument to all of the list elements. In this case we used add function of operator module which simply adds the given list arguments to an empty list.

Python3

   # Python3 program to unpack 
# tuple of lists
from functools import reduce
import operator
 
def unpackTuple(tup):
     
    return (reduce(operator.add, tup))
 
# Driver code
tup = (['a', 'apple'], ['b', 'ball'])
print(unpackTuple(tup))
 
  

Output:

['a', 'apple', 'b', 'ball']

Time complexity: O(n), where n is the total number of elements in all the lists combined in the tuple.
Auxiliary space: O(n), where n is the total number of elements in all the lists combined in the tuple. This is because the reduce function creates a new list that contains all the elements from the input lists.

Approach #2 : Using Numpy [Alternative to Approach #1]

Python3

   # Python3 program to unpack 
# tuple of lists
from functools import reduce
import numpy
  
def unpackTuple(tup):
      
    print (reduce(numpy.append, tup))
     
# Driver code
tup = (['a', 'apple'], ['b', 'ball'])
unpackTuple(tup)
 
  

Output:

['a' 'apple' 'b' 'ball']

Approach #3 : Using itertools.chain(*iterables) itertools.chain(*iterables) make an iterator that returns elements from the first iterable until it is exhausted, then proceeds to the next iterable, until all of the iterables are exhausted. This makes our job a lot easier, as we can simply append each iterable to the empty list and return it.

Python3

   # Python3 program to unpack 
# tuple of lists
from itertools import chain
 
def unpackTuple(tup):
    res = []
    for i in chain(*tup):
        res.append(i)
         
    print(res)
     
# Driver code
tup = (['a', 'apple'], ['b', 'ball'])
unpackTuple(tup)
 
  

Output:

['a', 'apple', 'b', 'ball']

Approach #4: Using extend()

Initialise empty list, iterate over tuple and use extend() method to add list elements to a initialised list.Finally display the new list

Python3

   # Python3 program to unpack
# tuple of lists
tup = (['a', 'apple'], ['b', 'ball'])
x=[]
for i in tup:
    x.extend(i)
print(x)
 
  

Output

['a', 'apple', 'b', 'ball']

Approach #5: Using a list comprehension: This approach involves using a list comprehension to iterate through the elements in the tuple of lists and create a new list containing all the elements. Here’s an example of how it could be done:

Python3

   # Tuple of lists
tup = (['a', 'apple'], ['b', 'ball'])
 
# Unpack tuple of lists using list comprehension
unpacked_list = [element for lst in tup for element in lst]
 
print(unpacked_list)
#This code is contributed by Edula Vinay Kumar Reddy
 
  