Could you please elaborate more on this important and complex notion?

Answer 1

Thank you for your help. The links are useful. Take care.

Answer 2

Your question is obscure, because you don't explicit the subject: if you only put it in tag, it's not easily readable ;)

Well, the topic is about 'generators", so I just googled few links ( I don't master that as much to success explaining in english ):

- about iterators, generators and decorators:
http://pymbook.readthedocs.io/en/latest/igd.html

- about generators ( and inseparate 'yield' instruction ) in particular:
http://www.learnpython.org/en/Generators
https://realpython.com/blog/JUMP_LINK__&&__python__&&__JUMP_LINK/introduction-to-python-generators/
https://jeffknupp.com/blog/2013/04/07/improve-your-python-yield-and-generators-explained/