Learning Python from various sources?

I'm learning Python, but looking at multiple sources:
1) https://www.udemy.com/courses/search/?q=python&src=ukw&p=3
2) Cybrary
3) Stackskills.com
Which one of these sites would have the most sufficient content for learning Python for the beginner?
1) https://www.udemy.com/courses/search/?q=python&src=ukw&p=3
2) Cybrary
3) Stackskills.com
Which one of these sites would have the most sufficient content for learning Python for the beginner?
Comments
You might also find some low cost books at http://www.packtpub.com and other places.
https://www.pluralsight.com/courses/python-beyond-basics
I have been working through a Stanford course and they use R, so while I am learning some R, what I want to learn is Python. Once this course is completed, turning full attention to Python
PS thanks for posting these links.
Just signed up for this and it's awesome!
Thanks!