In challenge 11, we have used ```generators``` to implement ```bash for i in ../*/*py; do grep ^import $i|sed 's/import //g' ; done | sort | uniq -c | sort -nr ``` How about redoing same challenge with Coroutines ? If interested, users can use below references. 1. [Curious Course on Coroutines and Concurrency](https://www.youtube.com/watch?v=Z_OAlIhXziw) 2. [Coroutines](http://www.dabeaz.com/coroutines/)