What Is idx In Python? Should You Be Using It?

So, do you want to know what the mysterious idx means in Python? Well, you are in luck, because today I am going to tell you. In Python, “idx” simply means “index”, the position of the element you are currently accessing. Not so hard, right? It is usually used in a context like this.

my_list = [21, 44, 35, 11]

# where "idx" = "index"
for idx, val in enumerate(my_list):
    print(idx, val)

# output
0 21
1 44
2 35
3 11

So why cut off the extra 2 characters and is “idx” really a proper way to be writing Python code?

Why Use The Variable idx In Python?

Honestly, it seems like this little variable is a lot more trouble than it’s worth. I remember when I first saw this variable name being used I was very confused. Now here you are, with the exact same confused expression on your face trying to figure out what it means as well.

Granted, once you understand that idx simply means index, it’s hard to forget, but why cut off the extra two letters? Well to be fair, the use of the variable name “idx” is very handy in a lot of Python programs so having a short-form does provide some value in the ability to write the name faster and still be interpreted as “index”.

In addition, it seems that this variable name has become a staple in Python the same way variable names such as i, j, and k have been for for-loops in the C language. For that reason, idx seems like a valid way to write the word index in loops in Python.

Should You Use idx in Python For Your Code?

Now that you know what idx means, should you be using it in your code? Well, that option is totally up to you. Since idx is a fairly standard way to write index in Python, there really is no harm in using it. Aside from confusing the Python noobies that haven’t seen the short-form before.

However, I would caution from using the short form in a company codebase unless the variable name has been used by someone else in the past. You know, for consistency.

So that’s pretty much it! If you are new to the Python language, good for you, it’s a great language to learn in 2022. If you are just getting started with Python, you can check out some great courses here.