Tuples

A tuple is an ordered, immutable sequence. Think of it as a list that has been locked.

point   = (3, 4)
rgb     = (255, 128, 0)
single  = (42,)       # trailing comma required for a 1-element tuple
empty   = ()
no_paren = 1, 2, 3    # parentheses are optional — the comma makes a tuple

Why immutability matters

Because a tuple cannot change, it can be used as a dictionary key or stored in a set — a list cannot.

# Valid — tuples are hashable
visited = {(0, 0), (1, 2), (3, 4)}
grid    = {(0, 0): "start", (3, 4): "end"}

# TypeError — lists are not hashable
bad = {[0, 0]: "start"}

Tuple packing / unpacking

# Packing
coords = 10, 20          # (10, 20)

# Unpacking
x, y = coords            # x=10, y=20

# Extended unpacking
first, *rest = (1, 2, 3, 4, 5)
# first=1, rest=[2, 3, 4, 5]

*head, last = (1, 2, 3, 4, 5)
# head=[1, 2, 3, 4], last=5

# Swap without a temp variable
a, b = 1, 2
a, b = b, a              # a=2, b=1

Named tuples

namedtuple gives each position a name, making code far more readable without adding overhead.

from collections import namedtuple

Point   = namedtuple("Point", ["x", "y"])
Color   = namedtuple("Color", ["red", "green", "blue"])

p = Point(3, 4)
c = Color(255, 128, 0)

print(p.x, p.y)          # 3 4
print(p[0], p[1])        # 3 4 — still indexable like a regular tuple
print(p)                 # Point(x=3, y=4)

# Immutable just like a plain tuple
p.x = 99                 # AttributeError

namedtuple vs dataclass

Both give named fields; the difference is mutability and ergonomics:

Feature	namedtuple	@dataclass
Mutable by default	✗	✓
Hashable / dict key	✓	only if frozen=True
Indexable by position	✓	✗
Default values	via defaults=	✓
Methods / validation	awkward	✓

Use namedtuple for lightweight, value-like records (coordinates, RGB, database rows). Use @dataclass when you need methods or mutable state.

Return multiple values from a function

Functions that return multiple values use tuple packing implicitly. Prefer namedtuple or @dataclass when the caller needs to know what each value means:

# Hard to read at the call site
def minmax(data): return min(data), max(data)
lo, hi = minmax([3,1,4,1,5])

# Self-documenting
MinMax = namedtuple("MinMax", ["min", "max"])
def minmax(data): return MinMax(min(data), max(data))
result = minmax([3,1,4,1,5])
print(result.min, result.max)