How to save StringListProperty from input type text - Appengine Python

I need to save the value of an input type text into a StringListProperty property in Google Appengine with Python.

If I try:

author.books = self.request.get('books')
author.put()

Then I get a 'Property books must be a list' error.

I need it to work with the following text in the input (2 or 1 books separated by commas):

• The Da Vinci Code, Angels & Demons
• Fahrenheit 451

Thanks for your help!

author.books = self.request.get('books').split(', ')