Python Lists » CDACian


Python Lists


Lists are used to store multiple items in a single variable.

A list in Python is used to store the sequence of various types of data. 

Lists are one of 4 built-in data types in Python used to store collections of data, the other 3 are Tuple, Set, and Dictionary, all with different qualities and usage.

Python lists are mutable type its mean we can modify its element after it created. However, Python consists of six data-types that are capable to store the sequences, but the most common and reliable type is the list.

A list can be defined as a collection of values or items of different types. The items in the list are separated with the comma (,) and enclosed with the square brackets [].

Lists are created using square brackets

thislist = ["apple", "banana", "cherry"]

Characteristics of Lists

The list has the following characteristics:

  • The lists are ordered.
  • The element of the list can access by index.
  • The lists are the mutable type.
  • The lists are mutable types.
  • A list can store the number of various elements.

List Methods

Python has a set of built-in methods that you can use on lists.
append()Adds an element at the end of the list
clear()Removes all the elements from the list
copy()Returns a copy of the list
count()Returns the number of elements with the specified value
extend()Add the elements of a list (or any iterable), to the end of the current list
index()Returns the index of the first element with the specified value
insert()Adds an element at the specified position
pop()Removes the element at the specified position
remove()Removes the item with the specified value
reverse()Reverses the order of the list
sort()Sorts the list

List Items

List items are ordered, changeable, and allow duplicate values.

List items are indexed, the first item has index [0], the second item has index [1] etc.


When we say that lists are ordered, it means that the items have a defined order, and that order will not change.

If you add new items to a list, the new items will be placed at the end of the list.


The list is changeable, meaning that we can change, add, and remove items in a list after it has been created.

Allow Duplicates

Since lists are indexed, lists can have items with the same value:

thislist = ["apple""banana""cherry""apple""cherry"]

List Length

To determine how many items a list has, use the len() function:

thislist = ["apple", "banana", "cherry"]


List Items - Data Types

List items can be of any data type:

list1 = ["apple", "banana", "cherry"]

list2 = [1, 5, 7, 9, 3]

list3 = [True, False, False]

A list can contain different data types:

A list with strings, integers and boolean values

list1 = ["abc", 34, True, 40, "male"]

The list() Constructor

It is also possible to use the list() constructor when creating a new list.

Using the list() constructor to make a List:

thislist = list(("apple", "banana", "cherry")) # note the double round-brackets


Python Collections (Arrays)

There are four collection data types in the Python programming language:

  • List is a collection which is ordered and changeable. Allows duplicate members.
  • Tuple is a collection which is ordered and unchangeable. Allows duplicate members.
  • Set is a collection which is unordered, unchangeable*, and unindexed. No duplicate members.
  • Dictionary is a collection which is ordered** and changeable. No duplicate members.

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