Python List Methods: A Practical Guide to Work with Lists

A method is a functionality provided by the Python list data type that can be called by specifying the list followed by a dot and followed by the method you want to call.

Some examples of methods supported by Python lists are append (adds an item to the end of a list), insert (adds an item at a specific position in a list), remove (removes an item from a list), sort (sorts a list), index (returns the index of the first element with a given value in a list).

When calling a method you usually pass an argument to it. Sometimes, you call a list method without passing any argument (e.g. with the pop() method).

Here is what the syntax to call a list method looks like:

list_name.method_name(argument)

What Methods Does a List Support in Python?

The examples in this tutorial are based on a list of integers that contains the first seven numbers of the Fibonacci sequence.

Open the Python shell on your computer and create the list below. You will use it to execute the examples of code in this tutorial:

fibonacci = [0,1,1,2,3,5,8]

Here is a table summarizing the most common methods supported by Python lists. This table will help you quickly identify list methods and remember how to use them.

To make this more interactive, open the Python shell, create the initial fibonacci list as mentioned before, and then execute all the commands in the table, one row at a time.

The updated list you will get from your Python shell must match the “Updated list” in the “Syntax Examples” column in the table.

Method	Description	Syntax Examples	Notes
append	Adds an item to the end of the list	fibonacci.append(13) Updated list: [0, 1, 1, 2, 3, 5, 8, 13]	–
remove	Removes the first item from the list with the given value	fibonacci.remove(3) Updated list: [0, 1, 1, 2, 5, 8, 13]	Raises ValueError if the value is not found
insert	Inserts an item at a specified position in the list	fibonacci.insert(4, 3) Updated list: [0, 1, 1, 2, 3, 5, 8, 13]	The first argument is the index, the second is the item to insert
pop	Removes and returns the item at the given position	number = fibonacci.pop(1) Updated list: [0, 1, 2, 3, 5, 8, 13]	Without an index, it removes and returns the last item
extend	Adds all elements from a list to the end of the current list	fibonacci.extend([21, 34]) Updated list: [0, 1, 2, 3, 5, 8, 13, 21, 34]	The argument must be an iterable. Raises a TypeError if the argument is not an iterable.
sort	Sorts the list in ascending order	fibonacci.sort() Updated list: [0, 1, 2, 3, 5, 8, 13, 21, 34]	Can take arguments for key and reverse for customization
reverse	Reverses the elements of the list in place	fibonacci.reverse() Updated list: [34, 21, 13, 8, 5, 3, 2, 1, 0]	–
index	Returns the index of the first element with the specified value	fibonacci.index(5) Result: 4	Raises ValueError if the value is not found in the list
count	Returns the number of times an element appears in the list	fibonacci.count(13) Result: 1	Returns zero if the element is not in the list

Useful Functions for Python Lists

The following table shows some common functions you can use with Python lists. The result you will get in your Python shell must match the “Result” in the “Syntax Examples” column.

Continue using the updated list you obtained after executing the reverse() method in the previous table:

[34, 21, 13, 8, 5, 3, 2, 1, 0]

Function	Description	Syntax Examples	Notes
len()	Returns the number of items in the list	print(len(fibonacci)) Result: 9	This is not a method, it’s a built-in function
min()	Returns the smallest item in the list	min(fibonacci) Result: 0	This is not a method, it’s a built-in function
max()	Returns the largest item in the list	max(fibonacci) Result: 34	This is not a method, it’s a built-in function
sum()	Returns the total sum of items in the list	sum(fibonacci) Result: 87	This is not a method, it’s a built-in function that works with numbers

More methods and functions are available and you can find them in the official Python documentation.

Conclusion

In this tutorial, you have learned several list methods and functions available that will allow you to work with lists in your programs. You now know how to:

• Add one element to the end of a list.
• Remove an element from a list.
• Add multiple elements to a list.
• Sort and reverse the elements of a list.
• Get the index of the first element with a specified value.
• Calculate the number of elements in a list.
• Get the smallest element, the largest element, and the sum of the elements in a list.

Let me know if you have any questions 🙂

Bonus read: now that you are more familiar with lists look at some simple exercises with Python lists.