Python Tuples

A tuple is like a list, but once it is created it cannot be changed.

Creating a Tuple

Write the items inside round brackets ():

python

location = (24.86, 67.00)
days = ("Mon", "Tue", "Wed", "Thu", "Fri")
print(location)
print(days[0])
print(len(days))

Output

(24.86, 67.0)
Mon
5

Tuples are ordered, unchangeable (immutable), and allow duplicates.

To make a tuple with only one item, you must add a comma. Without it, Python sees just a value in brackets.

python

a = ("Karachi",)
b = ("Karachi")
print(type(a))
print(type(b))

Output

<class 'tuple'>
<class 'str'>

Indexing and slicing work the same way as with lists:

python

colors = ("red", "green", "blue", "yellow")
print(colors[1])
print(colors[-1])
print(colors[1:3])
print("blue" in colors)

Output

green
yellow
('green', 'blue')
True

python

colors = ("red", "green", "blue")
colors[0] = "black"

Output

TypeError: 'tuple' object does not support item assignment

If you really need to change it, convert it to a list, change the list, and convert it back:

python

colors = ("red", "green", "blue")
temp = list(colors)
temp[0] = "black"
colors = tuple(temp)
print(colors)

Output

('black', 'green', 'blue')

You can take the values out of a tuple into separate variables in one line. This is called unpacking:

python

student = ("Ayesha", 20, "BSCS")
name, age, program = student
print(name)
print(age)
print(program)

Output

Ayesha
20
BSCS

Use * to collect the remaining items into a list:

python

scores = (95, 88, 76, 64, 50)
top, *others = scores
print(top)
print(others)

Output

95
[88, 76, 64, 50]

Tuples have only two methods:

Method	What it does
`count(x)`	How many times x appears
`index(x)`	Position of the first x

Use a list when	Use a tuple when
Items will be added or removed	The data should stay fixed
Example: a shopping cart	Example: GPS coordinates, days of the week

Tuples are a little faster than lists and protect your data from accidental changes. A function that returns several values actually returns a tuple.

How do you create a tuple with one item, "pen"?

("pen")("pen",)["pen"]{"pen"}