Python program to convert tuple into list by adding the given string after every element

Last Updated : 10 Apr, 2023

Given a Tuple. The task is to convert it to List by adding the given string after every element.

Examples:

Input : test_tup = (5, 6, 7), K = "Gfg" 
Output : [5, 'Gfg', 6, 'Gfg', 7, 'Gfg'] 
Explanation : Added "Gfg" as succeeding element.

Input : test_tup = (5, 6), K = "Gfg" 
Output : [5, 'Gfg', 6, 'Gfg'] 
Explanation : Added "Gfg" as succeeding element.

Method #1: Using list comprehension

In this, we construct a tuple of each element of tuple with a succeeding element and then run a nested loop to flatten each constructed tuple using list comprehension.

Python3

# Python3 code to demonstrate working of
# Convert tuple to List with succeeding element
# Using list comprehension

# initializing tuple
test_tup = (5, 6, 7, 4, 9)

# printing original tuple
print("The original tuple is : ", test_tup)

# initializing K
K = "Gfg"

# list comprehension for nested loop for flatten
res = [ele for sub in test_tup for ele in (sub, K)]

# printing result
print("Converted Tuple with K : ", res)

Output:

The original tuple is : (5, 6, 7, 4, 9)
Converted Tuple with K : [5, 'Gfg', 6, 'Gfg', 7, 'Gfg', 4, 'Gfg', 9, 'Gfg']

Time Complexity: O(n) where n is the number of elements in the tuple “test_tup”.
Auxiliary Space: O(n), where n is the number of elements in the new res list

Method #2 : Using chain.from_iterable() + list() + generator expression

This is similar to above method, difference is that nested loop is avoided by flattening using chain.from_iterable().

Python3

# Python3 code to demonstrate working of
# Convert tuple to List with succeeding element
# Using chain.from_iterable() + list() + generator expression
from itertools import chain

# initializing tuple
test_tup = (5, 6, 7, 4, 9)

# printing original tuple
print("The original tuple is : ", test_tup)

# initializing K
K = "Gfg"

# list comprehension for nested loop for flatten
res = list(chain.from_iterable((ele, K) for ele in test_tup))

# printing result
print("Converted Tuple with K : ", res)

Output:

The original tuple is : (5, 6, 7, 4, 9)
Converted Tuple with K : [5, 'Gfg', 6, 'Gfg', 7, 'Gfg', 4, 'Gfg', 9, 'Gfg']

Time Complexity: The time complexity of this program is O(n), where n is the length of the input tuple test_tup.

Auxiliary Space: The auxiliary space used by this program is O(n), where n is the length of the input tuple test_tup.

Method #3 : Using list(),map(),join(),split() methods

Python3

# Python3 code to demonstrate working of
# Convert tuple to List with succeeding element

# initializing tuple
test_tup = (5, 6, 7, 4, 9)

# printing original tuple
print("The original tuple is : ", test_tup)

# initializing K
K = "Gfg"
x = list(map(str, test_tup))
b = "*"+K+"*"
a = b.join(x)
c = a.split("*")
c.append(K)
res = []
for i in c:
    if(i != K):
        res.append(int(i))
    else:
        res.append(i)
# printing result
print("Converted Tuple with K : ", res)

Output :

The original tuple is : (5, 6, 7, 4, 9)
Converted Tuple with K : [5, 'Gfg', 6, 'Gfg', 7, 'Gfg', 4, 'Gfg', 9, 'Gfg']

Method #4 : Using map() function

Python3

# initializing tuple
test_tup = (5, 6, 7, 4, 9)

# printing original tuple
print("The original tuple is : ", test_tup)

# initializing K
K = "Gfg"

# using map
res = list(map(lambda x: [x, K], test_tup))
res = [j for i in res for j in i]

# printing result
print("Converted Tuple with K : ", res)
#This code is contributed by Vinay Pinjala.

Output

The original tuple is :  (5, 6, 7, 4, 9)
Converted Tuple with K :  [5, 'Gfg', 6, 'Gfg', 7, 'Gfg', 4, 'Gfg', 9, 'Gfg']

Time Complexity: O(n)

Auxiliary Space: O(n)

Method#5: Using Recursive method.

Algorithm:

Define a function called tuple_to_list_with_k that takes a tuple and a value k as arguments.
Check if the tuple is empty. If it is, return an empty list.
Otherwise, create a new list by concatenating the first element of the tuple with k, then recursively call the function on the rest of the tuple, and concatenate the result with the new list.
Return the list.

Python3

# Python3 code to demonstrate working of
# Convert tuple to List with succeeding element
# Using recursion
def tuple_to_list_with_k(tup, k):
    if not tup:
        return []
    else:
        return [tup[0], k] + tuple_to_list_with_k(tup[1:], k)

# initializing tuple
test_tup = (5, 6, 7, 4, 9)

# printing original tuple
print("The original tuple is : ", test_tup)

# initializing K
K = "Gfg"


res = tuple_to_list_with_k(test_tup,K)

# printing result
print("Converted Tuple with K : ", res)

Output

The original tuple is :  (5, 6, 7, 4, 9)
Converted Tuple with K :  [5, 'Gfg', 6, 'Gfg', 7, 'Gfg', 4, 'Gfg', 9, 'Gfg']

Time complexity: O(n), where n is the length of the input tuple. This is because the function processes each element of the tuple exactly once.

Space complexity: O(n), where n is the length of the input tuple. This is because the function creates a new list to store the output, which can have up to 2n elements (each element of the input tuple is followed by k). Additionally, the function uses the call stack to handle recursive calls, which can have up to n levels of recursion.