Python Lists

Features of a List

A list is a collection of objects. It contains the following features:

• It is ordered
• It is changeable
• It allows duplicate members

Create a list in Python

Access an item or items in a list

Lists are start at position 0. You can use slice notation like we covered in the strings chapter

Loop through a Python List

You can use a for loop to iterate through a list.

Check if an item exists in a list

Use the “in” keyword to check if an item exists in a list.

Get the length of a Python List.

Use the len() method to get the length of a list

Sort a Python List

Use the sort() method to sort a list.

Reverse sort items in a Python List

Use the reverse() method to reverse sort a list.

Add a single item to a Python List

Add a single item to a Python list using the append() method.

Add multiple items to a Python List

Add multiple items to a Python List using the extends() method.

Add an item to a Python List at a specific Location

To add an item to a list at a specific location use the insert() method.

Remove an item from a Python List by index using pop()

To remove an item from a Python List by index use the pop() method.

Remove an item from a Python List by index using del keyword

To remove an item from a Python List by index use the del keyword.

Remove an item from a Python List by value

To remove an item from a Python List by value use the remove() method.

Remove all items from a Python List (empty a list)

To remove all items from a Python List use the clear() method.