Which Python Framework to use for my upcoming project?

I am currently working as a web developer. My current project is about developing a visualization tool for monitoring heart rate and accelerometer data of traumatic patients. Currently I am using Flask and SQLAlchemy for this project.

I will start working on another project of an online educational web portal for patients suffering from epilepsy. I am thinking of using Django and MySql to develop the portal. The reason for that is to learn a new technology and understand the difference.

Is choosing a new technology a good idea or should I stick to using Flask framework? All other projects in my lab are done using Flask SQLAlchemy.