SHA-2 (Secure Hash Algorithm 2), of which SHA-256 is a part, is one of the most popular hashing algorithms out there. In this article, we are going to break down each step of the algorithm as simple as we can and work through a real-life example by hand.
Source: How SHA-2 Works Step-By-Step (SHA-256), an article by Lane Wagner.
What makes a picture good? Not only because this is a very subjective question it is a hard one to answer. We will still try to do that and in the process we will also come across the following questions: why do you take pictures in the first place and: for whom?
Source: What makes a picture good?
Every time you create an instance of a class in Python, you are using up some memory–including overhead that might actually be larger than the data you care about. Create a million objects, and you have a million times the overhead.
And that overhead can add up, either preventing you from running your program, or increasing the amount of money you spend on provisioning hardware.
So let’s see how big that overhead really is (sneak preview: it’s large!) and what you can do about it.
Source: Too many objects: Reducing memory overhead from Python instances, an article by Itamar Turner-Trauring.