How is it that json serialization is so much faster than yaml serialization in Python?

Question

I have code that relies heavily on yaml for cross-language serialization and while working on speeding some stuff up I noticed that yaml was insanely slow compared to other

Answer 1

Speaking about efficiency, I used YAML for a time and felt attracted by the simplicity that some name/value assignments take on in this language. However, in the process I tripped so and so often about one of YAML’s finesses, subtle variations in the grammar that allow you to write special cases in a more concise style and such. In the end, although YAML’s grammar is almost for certain formally consistent, it has left me with a certain feeling of ‘vagueness’. I then restricted myself to not touch existing, working YAML code and write everything new in a more roundabout, fail-safe syntax—which made me abandon all of YAML. The upshot is that YAML tries to look like a W3C standard, and produces a small library of hard to read literature concerning its concepts and rules.

This, I feel, is by far more intellectual overhead than needed. Look at SGML/XML: developed by IBM in the roaring 60s, standardized by the ISO, known (in a dumbed-down and modified form) as HTML to uncounted millions of people, documented and documented and documented again the world over. Comes up little JSON and slays that dragon. How could JSON become so widely used in so short a time, with just one meager website (and a javascript luminary to back it)? It is in its simplicity, the sheer absence of doubt in its grammar, the ease of learning and using it.

XML and YAML are hard for humans, and they are hard for computers. JSON is quite friendly and easy to both humans and computers.