Python Lists

Lists are one of the most common and versatile data structures used in Python. A list is a collection of items that can be of any data type - be it numbers, strings, or other complex types like functions and objects. A list is mutable, which means its values can be changed even after it has been created. In Python, lists are denoted by square brackets [].

Syntax

list_name = [item1, item2, item3, ..., item_n]

Each item can be of any data type. Items are separated by commas.

Example

# Creating a list of integers
numbers = [1, 3, 5, 7, 9]

# Creating a list of strings
fruits = ["apple", "banana", "cherry"]

# Creating a mixed-type list
mixed = [1, "apple", True, None, ["nested", "list"]]

Output

The values of a list can be accessed by index, starting from 0 for the first value. We can use the print function to display the values of a list.

# Accessing values of a list
print(numbers[0]) # Output: 1
print(fruits[1]) # Output: banana
print(mixed[4][1]) # Output: list

Explanation

• Lists are denoted by square brackets [].
• Each item in a list is separated by a comma.
• Items in a list can be of any data type.
• Items in a list can be accessed by index, starting from 0 for the first value.
• Lists are mutable, i.e., their values can be changed.

Use

Lists can be used to store and manipulate data of different types. They are used extensively in Python programming due to their versatility and wide range of functions built-in.

Some common operations performed on lists include:

• Accessing values based on their index
• Adding new items to a list
• Removing items from a list
• Sorting a list
• Looping over items in a list

Important Points

• Lists are mutable, meaning their values can be changed
• Lists are ordered, meaning they retain the order of their values
• Lists can contain items of any data type
• Lists support indexing and slicing
• Lists can be nested, i.e., a list can contain other lists as values

Summary

Lists are a versatile and valuable tool in Python programming. They allow us to store and manipulate data of all types and perform various operations on them. Understanding lists is an essential part of Python programming, and they are frequently used in code snippets, programs, and larger applications.