Iterables

Iterables are objects that can be iterated over, like lists, tuples, dictionaries, sets, strings, and generators.

List

List is a collection of items that can be of different types (heterogeneous).

my_list = [1, 2, 3, 4, 5]
my_list = ["Hello", "World"]
my_list = [1, "Hello", 3.4, True]

# Accessing items
print(my_list[0]) # 1

Featues:

Lists are mutable, meaning that you can change their content after creation.
Lists are ordered, meaning that the items have a defined order, and that order will not change.
Lists allow duplicate values, meaning that you can have two items that are the same.

Tuple

Tuple is a collection of items that can be of different types (heterogeneous).

my_tuple = (1, 2, 3, 4, 5)
my_tuple = ("Hello", "World")
my_tuple = (1, "Hello", 3.4, True)

# Accessing items
print(my_tuple[1]) # Hello

Featues:

Tuples are immutable, meaning that you can’t change their content after creation.
Tuples are ordered, meaning that the items have a defined order, and that order will not change.
Tuples allow duplicate values, meaning that you can have two items that are the same.

Note

Tuples are more memory efficient and faster (looking up values) than the lists. If you have data that shouldn’t change, you should choose tuple data type over lists

Dictionary

Dictionary is a collection of items that can be of different types (heterogeneous). Dictionary is a collection of key-value pairs. Dictionaries are useful for fast lookups and retrieval of values based on keys.

my_dict = {
    "name": "John",
    "age": 36,
    "country": "Norway"
}

# Accessing items
print(my_dict["name"]) # John
print(my_dict.get("name")) # John

Set

Set is a collection of items that can be of different types (heterogeneous). Sets contain only unique values. Sets are used to store multiple items in a single variable.

my_set = {1, 2, 3, 4, 5}
my_set = {"Hello", "World"}
my_set = {1, "Hello", 3.4, True}

# Accessing items
for item in my_set:
    print(item)

Featues:

The elements of the set are immutable in nature, that is, they cannot be changed. However, a set itself is mutable (we can add or remove items from it)
Unordered
Duplicates Not Allowed. Sets cannot have two items with the same value.

Array

Array is a collection of items of the same type (homogeneous) Array is faster than list. Array must be declared before they can be used because they are not part of the standard Python.

from array import array

int_array = array('i', [1, 2, 3, 4, 5])
gloat_array = array('f', [1.1, 2.2, 3.3, 4.4, 5.5])