Implementation of some useful molecular descriptors

[GardevoirX]

Backgrounds

As mentioned in README, the base of this machine learning project is the molecular descriptors.

Requirements

We need to implement more molecular descriptors, like $\log P$ (Partition coefficient (oil/ water)), topological polar surface area (TPSA), numbers related to H-Bonds (like donor, acceptor), solvent accessible surface area (SASA), number of rotatable bonds and number of aromatic rings.

TODO

• Implement the six descriptors mentioned above in descriptors.py based on the abstract class DescriptorsABC
• Add the new classes implemented into AVAILABLE_DESCRIPTORS
• Pass pytests

References

1. https://www.rdkit.org/docs/source/rdkit.Chem.Crippen.html
2. https://www.rdkit.org/new_docs/source/rdkit.Chem.rdMolDescriptors.html