For sure I do not want to return to the coding style like 

 S f="inputfile.txt" O f U f F  R l D

 . Q:l="***END***"

 . D ##class(process).Input(l)

But working with Python seems to be broadly accepted all over the globe without questioning the syntax of it. In other words: I agree with Robert. There is no perfect programming language and it is always painful to read a code written in an "unknown" language. On the other hand it does not mean that a programmer should not care about code maintainability. So what is the point? Everyone must find the balance between coding efficiency and readability. And tools are just tools helping us find the balance. 

My suggestion: create an interim XSL file and copy-paste before debugging...

Thanks for the comments. This article is mainly for beginners and focusing on how to build RESTful services. Yes, selecting the right testing tool could be important. But let us help the beginners to buld their first service, let them try (using something) and once they are able to "fly" write them an article "Selecting the best tool for  testing RESTful services".