Is there a convention on how to write pseudocode in scientific papers?
As you are already stating: There is no norm / convention for pseudocode. 

Personally, I prefer a python-like notation, but this is because I like python ;-). CLRS is fine for many purposes. 

If your software is written in a specific language, it might be beneficial to use a code convention which allows you to express the specifics of your programming language - this reduces the risk of introducing errors. 

Even more important then the code convention is, that you should ensure your pseudocode allows someone else to re-implement your code without room for interpretations. Sometimes, "real" code can be more appropriate (but yes, it can be lengthy).