How To Remove Duplicates From A List In Python

Though it takes some time to get to grips with and really learn the ins and outs, Python is a very intuitive and advanced programming language that can help you to really feel a sense of control.

However, it takes a lot of practice and trial and error to learn everything that is possible with the Python program, and as such, you may find yourself wondering how to do things such as removing duplicates from lists.

How To Remove Duplicates From A List In Python

If you’ve found yourself troubled by duplicates showing up while using Python, you’re likely here because you want ot figure out how to be rid of them, once and for all, right?

Don’t worry, because we are going to show you how to do just that! Read on below!

What Is A List In Python?

A list, within the context of Python, refers to an immutable structure of data that is intended to categorize the data in an ordered sequence.

Each of the parts of an individual list is called an item or an element. To differentiate themselves from strings, which are denoted by (“) symbols,  lists are denoted via square brackets ([]).

How Do You Remove Duplicates From A List In Python?

Luckily, there is a really great work-around that you can make use of in order to quickly eliminate all duplicates from a given list.

What it involves is creating a dictionary of every single element involved in the list. 

Identify Your List

To start with, you are going to want to make sure that you have identified the correct list in the Python program that contains the duplicates that you wish to eliminate.

Once you have found your list, simply enter a new command line below it.

Create Your Dictionary

Once you have created your new command line, type into it “dict.fromkeys(mylist)” This will cause the program to create a dictionary that catalogs everything involved in the list.

The clever thing about this trick is that dictionaries within python cannot have duplicate items in them. Thus, it will eliminate any duplicates while the dictionary is being produced.

Convert The Dictionary To A List

Once you have created your dictionary, all you then need to do is to convert that dictionary into a new list. In order to do that, you will need to type “mylist = list ( )” with the previous dictionary-creating command inserted between the last two brackets.

This will cause the dictionary to be converted into a list, and you will notice that it has returned the elements of the list into the original order, but without the duplicate elements. 

If you want to see the result of the conversion yourself, you will then want to print the list, which will show you the list in a demonstrated form. In order to do this, simply type “print(mylist)”.

This will present you with your new list, now without the inclusion of the duplicate elements! 

Can You Create A Function To Remove Duplicates From Lists In Python?

Yes. If you find that duplicates show up in your lists quite frequently while using Python, then you may be well suited in creating your own duplicate-removing function.

How To Remove Duplicates From A List In Python

This is quite easy to do and can be used in the future to filter your lists so that duplicates will be removed in an efficient way that does not compromise your data.

Create Your Function

The first step you need to take is to create the function itself, this can be done by typing out “def my_function(x):”. This will create a function that operates by taking a list and using it to operate.

Once you have done that, simply type underneath it, on a new command line, “dict.fromkeys(x)” this will create a dictionary that can then remove all duplicates from any lists. 

Convert The Dictionary To A List

From here, you simply convert the dictionary into a list, using the same commands we showed you earlier, before then returning that list.

This can be done by, in front of the list on the terminal interface, typing “return”. “Return” causes the result of any function to be presented to you so that when you use the function in the future, you will be presented with your new duplicate-free list.

Call Your New Function

Once you have created your new function, all you then need to do is call it, which will ensure that it works again in the future. This is done by typing “mylist = my_function( [LIST HERE] )”. 

Frequently Asked Questions

What Is A List Used For?

Luckily, a list within Python follows much the same logic that a list in real life would follow. A list within Python will take all of the elements contained within it, and order them in a logical way that you can change to suit your needs.

Thus, lists are useful to help you to order data and to categorize things within the Python program.

What Is List And Tuple In Python?

Both lists and tuples within Python are very similar, as they are both data structures that can store multiple elements.

The major difference is that lists are declared using square brackets, while tuples are declared using circle brackets!

What Is Python Coding Used For?

Python’s coding language is most commonly used to help create websites and software for users to depend on. Python can be used to create all sorts of programs, and this has helped to make it a very popular coding language across the world.

To Wrap Up

As you can see, removing duplicates from a list in Python is not too challenging, and just requires a little bit of ingenuity in leveraging the fact that dictionaries in Python do not include duplicates!

You can also easily create a reusable function that you can utilize in the future to help you to eliminate future duplicates that show up in your lists. 

We hope that this guide has proven useful and that you now feel ready to take on the task of eliminating duplicates from your Python lists. It is easier than it looks, and is incredibly useful.