Added 3 screencast on list

free-podcasts-screencasts-en.md

 ### Index
+* [Python](#python)
 * [Ruby](#ruby)
 
+### Python
+* [Screencast] - [ShowMeDo - Python Videos, Tutorials and Screencasts](http://showmedo.com/videotutorials/python)
+* [Screencast] - [Diving into Django](http://code.tutsplus.com/articles/diving-into-django--net-2969)
+* [Screencast] - [Try Django Tutorial](http://youtu.be/3DccH9AMwFQ?list=PLEsfXFp6DpzRgedo9IzmcpXYoSeDg29Tx)
 
 ### Ruby
 * [Podcast] - [5by5 - Ruby on Rails Podcast](http://5by5.tv/rubyonrails)