How to enable pip, QPython to write to Android filesystem?

I have been following this guide to install youtube-dl on my Android phone. http://www.arulraj.net/2015/11/download-any-videos-in-android-using-youtube-dl.html However, when downloading the videos, I get the following error. ERROR: unable to open for writing: [Errno 30] Read-only file system: How would I be able to give write permissions to the pip console of QPython so I can write to a folder on /sdcard? Running Android Marshmallow 6.0 with root access.