Tisbury Treasure Hunt

In Python, a tuple is an immutable collection of items in sequence. Like most collections, tuples can hold any (or multiple) data type(s) -- including other tuples. Tuples support all common sequence operations, but do not support mutable sequence operations.

The elements of a tuple can be iterated over using the for item in <tuple> construct. If both element index and value are needed, for index, item in enumerate(<tuple>) can be used. Like any sequence, elements within tuples can be accessed via bracket notation using a 0-based index number from the left or a -1-based index number from the right. Tuples can also be copied in whole or in part using slice notation (<tuple>[<start>:<stop>:<step>]).

Tuple Construction

Tuples can be formed in multiple ways, using either the tuple(<iterable>) class constructor or the tuple literal declaration.

Using the tuple() constructor empty or with an iterable:

>>> no_elements = tuple()
()

# The constructor *requires* an iterable, so single elements must be passed in a list or another tuple.
>>> one_element = tuple([16])
(16,)

Strings are iterable, so using a single str as an argument to the tuple() constructor can have surprising results:

# String elements (characters) are iterated through and added to the tuple
>>> multiple_elements_string = tuple("Timbuktu")
('T', 'i', 'm', 'b', 'u', 'k', 't', 'u')

Single iterables have their elements added one by one:

>>> multiple_elements_list = tuple(["Parrot", "Bird", 334782])
("Parrot", "Bird", 334782)

>>> multiple_elements_set = tuple({2, 3, 5, 7, 11})
(2,3,5,7,11)

Declaring a tuple as a literal :

Because the tuple(<iterable>) constructor only takes iterables (or nothing) as arguments, it is much easier to create a one-tuple via the literal method.

>>> no_elements = ()
()

>>> one_element = ("Guava",)
("Guava",)

Nested data structures can be included as tuple elements, including other tuples:

>>> nested_data_structures = ({"fish": "gold", "monkey": "brown", "parrot" : "grey"}, ("fish", "mammal", "bird"))
({"fish": "gold", "monkey": "brown", "parrot" : "grey"}, ("fish", "mammal", "bird"))

>>> nested_data_structures_1 = (["fish", "gold", "monkey", "brown", "parrot", "grey"], ("fish", "mammal", "bird"))
(["fish", "gold", "monkey", "brown", "parrot", "grey"], ("fish", "mammal", "bird"))

Tuple Concatenation

Tuples can be concatenated using plus + operator, which unpacks each tuple creating a new, combined tuple.

>>> new_via_concatenate = ("George", 5) + ("cat", "Tabby")
("George", 5, "cat", "Tabby")

#likewise, using the multiplication operator * is the equivalent of using + n times
>>> first_group = ("cat", "dog", "elephant")

>>> multiplied_group = first_group * 3
('cat', 'dog', 'elephant', 'cat', 'dog', 'elephant', 'cat', 'dog', 'elephant')

Accessing Elements Inside a Tuple

Elements within a tuple can be accessed via bracket notation using a 0-based index number from the left or a -1-based index number from the right.

student_info = ("Alyssa", "grade 3", "female", 8 )

#gender is at index 2 or index -2
>>> student_gender = student_info[2]
'female'

>>> student_gender = student_info[-2]
'female'

#name is at index 0 or index -4
>>> student_name = student_info[0]
Alyssa

>>> student_name = student_info[-4]
Alyssa

Iterating Over a Tuples Elements

Elements inside a tuple can be iterated over in a loop using for item in <tuple> syntax. If both indexes and values are needed, for index, item in enumerate(<tuple>) can be used.

>>> student_info = ("Alyssa", "grade 3", "female", 8 )
>>> for item in student_info:
...   print(item)

...
Alyssa
grade 3
female
8

>>> for index, item in enumerate(student_info):
...  print("Index is: " + str(index) + ", value is: " + str(item) +".")

...
Index is: 0, value is: Alyssa.
Index is: 1, value is: grade 3.
Index is: 2, value is: female.
Index is: 3, value is: 8.

Checking Membership in a Tuple

The in operator can be used to check membership in a tuple.

>>> multiple_elements_list = tuple(["Parrot", "Bird", 334782])
("Parrot", "Bird", 334782)

>>> "Parrot" in multiple_elements_list
True