Even “Senior” developers often forget to use indexes in Django. You can’t imagine how faster it can get if you simply add two lines of code into your model!

In this article we will take measurements together: with and without indexes.

Setup

Our patient will be a small Django application with just 7 fields.

I will just show the model here:

class Student(models.Model):
    first_name = models.CharField(max_length=100)
    last_name = models.CharField(max_length=100)
    code0 = models.CharField(max_length=100, blank=True)
    code1 = models.CharField(max_length=100, blank=True)
    code2 = models.CharField(max_length=100, blank=True)
    code3 = models.CharField(max_length=100, blank=True)
    code4 = models.CharField(max_length=100, blank=True)

We have a lot of CharFields. No indexes.

We will be testing…

Step by step guide to writing Tetris in Python with PyGame

In this tutorial, we will write a simple Tetris using the PyGame library in Python. The algorithms inside are pretty simple but can be a little challenging for the beginners. We will not concentrate on PyGame mechanics too much, but rather focus on the game logic. If you are too lazy to read all the stuff, you may simply copy and paste the code in the end.

Prerequisites

1. Python3. This may be downloaded from the official website.
2. PyGame. Go to your command prompt or terminal, depending on the OS you…

A quick tip: How to reuse the Django built-in authentication forms

Do you need to authenticate your users but don’t want to write HTML with CSS, add views for that, and add that view to the urls.py?

I know this feeling, and I am here to help you!

Most probably, you already have this path in your url patterns:

path('admin/', admin.site.urls),

And now, just add this to any of your views:

def index(request):
    if request.user.is_anonymous:
        return redirect("/admin/login/?next=/")
    ...

So, if the user is not authenticated, he/she will be redirected to the default login view of the Django system, and then…

One of the ways to find a path is a recursive algorithm called “Depth-First Search”. If you thought that recursion is needed only for finding a factorial, you will be surprised.

Since we animate our algorithm, we will not go through all combinations and find the shortest path. We will find at least one path and will be happy with it. But sure you may go ahead and find all possible combinations, but you better do it in a normal graph, not a maze.

When do we need it?

Good question, thanks for asking.

It’s not a good idea to use it for finding a…

You know that it is bad to put your passwords in code. You git push it. Python code isn’t even compiled, so everyone can see it. And it is not convenient when you have different database connections on your machine and on the server.

Solution: Use Environment Variables

In this article, I will show you how to keep these variables in different Operating Systems and how to read them in Python.

When you publish your masterpiece to the Cloud, you set up a PostgreSQL server, and then the hell starts. Namely, you need to put your connection settings and the…

There are many articles that explain how Caching works in Django. Most of them are complicated, so I decided to simplify everything for you.

Why Cache?

You may have some pages in your application that do not change so often. Your application still has to call your function and render an HTML.

It’s even worse if that is some statistics that should be computed and has access to your database. For example, it may be the number of views of a video on YouTube. Or the number of likes.

To calculate the number of views of a video, the server needs to…

Most of these jokes have been found in Russian. Since I have not found the English version on the Internet, I decided to translate them for you. I truly hope you will enjoy this article!

0. Do you follow the Stack Overflow Driven Development (SODD) approach?

1. Have you ever been charged for storing your data in global variables?

2. What is the result of the following command?

git push me and then just touch me till I can get my satisfaction, satisfaction

3. Have you ever done .Net for money?

4. You have stated in your CV that you…

A quick intro to decorators in Python

You have seen and used decorators many times. But it was always magic for you.

It is time to finally understand decorators in Python.

Why use decorators?

Usually, this is an easy way to modify a lot of functions.

For example, you want to make sure that only authorized users are accessing this function.

Or you want to avoid printing something to the console. But only for some functions. And you want to quickly turn this feature on and off.

Or you want to do some preprocessing to your parameters first.

The good thing is that…