Gevent: is it a good practice to yield in each for-loop iteration?

Question

I'm coming from Node.js where libraries such as https://github.com/caolan/async allow to iterate asynchronously through arrays without blocking the event loop.

am I correct that achieving the same with Gevent can be done by calling sleep(0) on each loop iteration ?

is this actually necessary for a web server while parsing db queries or the blocking time of Python code (not IO operations) is negligible ?

Answer 1

Gevent has the gevent.idle() call just for that purpose (which seems to be undocumented: http://www.gevent.org/gevent.html#useful-general-functions).

However, if you are sure that the loop will do some time consuming CPU heavy processing, it's better to offload it to a truly parallel worker using multiprocessing or Threads, but keep in mind that you have to take extra measures to make these work with Gevent nicely.