Tuples

A tuple is like a list, but immutable: once created it can’t change. It uses parentheses.

point = (10, 20)
colors = ("red", "green", "blue")

Access

print(point[0])    # 10
print(colors[-1])  # blue

You can’t change it

point[0] = 5   # TypeError

To “change” it, convert to a list, edit, and convert back:

tmp = list(point)
tmp[0] = 5
point = tuple(tmp)

Unpack

x, y = point
print(x)   # 5
print(y)   # 20

Why use a tuple

• Data that shouldn’t change (coordinates, settings).
• Lighter and faster than a list.
• Can be a dictionary key (a list can’t).

Single-item tuple

You need the comma:

t = (5,)   # tuple
x = (5)    # just the number 5