Change the implementation of the metadata structure #3
Description
In this moment the Metadata structure in Pandas is implemented as a Dataframe of lists. But this makes the selection and filtering of samples based on metadata pretty difficult and verbose.
Change that needs to be done:
- Encapsulate the python list of metadata value in an object (called, for example MetaCell)
- Overload the operators in order to make the syntax coherent with GMQL
- Overload the toString function for good visualization in Pandas