tuple() Constructor in Python

In Python, the tuple() constructor is a built-in function that is used to create tuple objects. A tuple is similar to a list, but it is immutable (elements can not be changed after creating tuples). You can use the tuple() constructor to create an empty tuple, or convert an iterable (such as a list, string, or range) into a tuple.

Example:

# Example
t1 = tuple()            # creates an empty tuple
t2 = tuple([1, 2, 3])   # converts a list into a tuple
t3 = tuple("Python")    # converts a string into a tuple

print(type(t1), t1)
print(type(t2), t2)
print(type(t3), t3)

<class 'tuple'> ()
<class 'tuple'> (1, 2, 3)
<class 'tuple'> ('P', 'y', 't', 'h', 'o', 'n')

Syntax of tuple()

tuple([iterable])

• iterable: This is an optional argument. If provided, tuple() will convert the iterable (like a list, string, or range) into a tuple.
• If no iterable is passed, it creates an empty tuple ().

Use of Tuple() Constructor

The tuple() constructor is mainly used to:

• Create an empty tuple.
• Convert other iterables, such as lists, strings, ranges, etc., into tuples.

Let's see some examples:

Convert a Range to a Tuple

The range() function creates a range object, and we can use tuple() to convert it into a tuple.

t = tuple(range(5))  
print(t) 

(0, 1, 2, 3, 4)

Convert a List Comprehension to a Tuple

Here, we are converting a tuple from a generator expression, which squares each number in the range from 0 to 4.

t = tuple(x * x for x in range(5))
print(t) 

(0, 1, 4, 9, 16)

Creating Nested Tuples

You can also create nested tuples using the tuple() constructor. Here's an example where we create a tuple of tuples, forming a 2D structure.

mat = tuple([tuple(range(3)) for _ in range(3)])  
print(mat)

((0, 1, 2), (0, 1, 2), (0, 1, 2))

Shallow Copy of a Tuple Using tuple()

Since tuples are immutable, you cannot change their elements once created. However, you can create a shallow copy of a tuple by using the tuple() constructor. This might be useful when you want to duplicate a tuple object.

t1 = ([1, 2], [3, 4])
t2 = tuple(t1)

t2[0][0] = 10    # Modifies the list inside tuple
print(t1)        # Output: ([10, 2], [3, 4])

([10, 2], [3, 4])

Explanation: In this case, although b and b1 are separate tuples, the lists inside them are not copied, so changes to the lists inside b1 will reflect in b.