Tuple Syntax

Note

Source: Python-specific — C# has no direct equivalent in this edition. Python tuples are the immutable counterpart to lists. Use them when a fixed-size, ordered collection should not be modified after creation.

A tuple is an ordered, immutable sequence of values. Once created, its elements cannot be changed.

Creating Tuples

Write a tuple with parentheses and commas:

point = (3, 7)
rgb = (255, 128, 0)
empty = ()

Parentheses are optional in most contexts — the comma is what makes a tuple:

point = 3, 7        # also a tuple
print(type(point))

Output:

<class 'tuple'>

A single-element tuple requires a trailing comma; without it, Python treats the parentheses as grouping:

one = (42,)         # tuple with one element
not_one = (42)      # just the integer 42
print(type(one), type(not_one))

Output:

<class 'tuple'> <class 'int'>

Indexing and Length

Tuples support indexing, slicing, and len() exactly like lists:

rgb = (255, 128, 0)
print(rgb[0])        # 255
print(rgb[-1])       # 0
print(len(rgb))      # 3

Immutability

Attempting to change an element raises a TypeError:

rgb = (255, 128, 0)
rgb[0] = 100     # TypeError: 'tuple' object does not support item assignment

Tuples vs. Lists

Tuple	List
Immutable	Mutable
(1, 2, 3)	[1, 2, 3]
Can be a dict key	Cannot be a dict key
Slightly faster	More flexible

Use a tuple when the structure is fixed by design: a coordinate, an RGB colour, a database record field.

Use a list when items will be added, removed, or reordered.

Converting Between Tuples and Lists

t = (1, 2, 3)
lst = list(t)       # convert tuple → list
lst.append(4)
t2 = tuple(lst)     # convert list → tuple
print(t2)

Output:

(1, 2, 3, 4)