Black is the uncompromising Python code formatter. By using it, you agree to cede control over minutiae of hand-formatting. In return, Black gives you speed, determinism, and freedom from pycodestyle nagging about formatting. You will save time and mental energy for more important matters.
However some top of the book update can result in an entire level disappearing. In that case, both price and volume changed actually at the same time, yet according to this example it will be broken down into two messages? This will lead to inconsistent state of the book when I read it between two messages. Or did the example just happen to show one field per message, and multiple fields per message are possible too?
Back in the day `aws ec2 get-console-output --instance-id $ID` used to contain the public key that can be extracted using regex. Not sure if this still works.