Python | Convert a List into a Tuple

Given a list, write a Python program to convert the given list into a Python tuple. 

Examples:

Input : [1, 2, 3, 4]
Output : (1, 2, 3, 4)

Input : ['a', 'b', 'c']
Output : ('a', 'b', 'c')

Convert a list into a  tuple using tuple()

Using tuple(list_name). Typecasting to tuple can be done by simply using tuple(list_name). 

Python3

# Python3 program to convert a
# list into a tuple
def convert(list):
    return tuple(list)

# Driver function
list = [1, 2, 3, 4]
print(convert(list))

Output

(1, 2, 3, 4)

Time complexity: O(n)
Auxiliary space: O(n)

A small variation to the above approach is to use a loop inside tuple() . 

Python3

# Python3 program to convert a
# list into a tuple
def convert(list):
    return tuple(i for i in list)

# Driver function
list = [1, 2, 3, 4]
print(convert(list))

Output

(1, 2, 3, 4)

Time complexity: O(n), where n is the length of the input list.
Auxiliary space: O(n), as a new tuple is created to store the converted elements of the list

Convert a list into a  tuple Using *list

Using (*list, ) This essentially unpacks the list l inside a tuple literal which is created due to the presence of the single comma (, ). This approach is a bit faster but suffers from readability. 

Python3

# Python3 program to convert a
# list into a tuple
def convert(list):
    return (*list, )

# Driver function
list = [1, 2, 3, 4]
print(convert(list))

Output

(1, 2, 3, 4)

Convert a list into a  tuple Using map and lambda

This program uses the map() function and lambda to convert a list of integers to a list of strings, and then uses the join() method to concatenate the strings in the list with a comma separator.

Approach:

1. Create a list of integers [1, 2, 3, 4].
2. Use the map() function and lambda to convert each integer in the list to its corresponding string representation, resulting in a list of strings [‘1’, ‘2’, ‘3’, ‘4’].
3. Use the join() method to concatenate the strings in the list with a comma separator, resulting in a single string ‘1,2,3,4’.
4. Print the final string as the output.

Python3

# use the map() function and lambda
# to create a list of strings
strings_list = list(map(lambda x: str(x),
                        [1, 2, 3, 4]))

# use the join() method to concatenate the
# strings in the list with a comma separator
output_str = ",".join(strings_list)

# print the final string
print(output_str)  # 1,2,3,4

Output

1,2,3,4

Convert a list into a tuple without Using builtin function

Here we are not going to use any function for typecasting.

Python3

# Function to convert a list to a tuple
def convert_list_to_tuple(lst):
    tuple_result = ()  # Empty tuple to store the converted elements
    for element in lst:
        tuple_result += (element,)  # Append each element to the tuple
    return tuple_result

# Example usage
my_list = [1, 2, 3, 4]
my_tuple = convert_list_to_tuple(my_list)
print(my_tuple)

Output:

(1, 2, 3, 4)