merge duplicated codes for building featurizers

        featurizer = rgf.RdkitGridFeaturizer(

            voxel_width=2.0,

            feature_types=[

            'ecfp', 'splif', 'hbond', 'salt_bridge', 'pi_stack', 'cation_pi',

            'charge'

                'ecfp', 'splif', 'hbond', 'salt_bridge', 'pi_stack',

                'cation_pi', 'charge'

            ],

            flatten=True)

  elif featurizer == "atomic":

    elif featurizer == "atomic" or featurizer == "atomic_conv":

        # Pulled from PDB files. For larger datasets with more PDBs, would use

        # max num atoms instead of exact.

        frag1_num_atoms = 70  # for ligand atoms

        if load_binding_pocket:

            frag2_num_atoms = 1000

            complex_num_atoms = 1070

        max_num_neighbors = 4

        # Cutoff in angstroms

        neighbor_cutoff = 4

        if featurizer == "atomic":

            featurizer = ComplexNeighborListFragmentAtomicCoordinates(

        frag1_num_atoms, frag2_num_atoms, complex_num_atoms, max_num_neighbors,

        neighbor_cutoff)

  elif featurizer == "atomic_conv":

    frag1_num_atoms = 70  # for ligand atoms

    if load_binding_pocket:

      frag2_num_atoms = 1000  # for protein atoms

      complex_num_atoms = 1070  # in total

    else:

      frag2_num_atoms = 24000  # for protein atoms

      complex_num_atoms = 24070  # in total

    max_num_neighbors = 4

    # Cutoff in angstroms

    neighbor_cutoff = 4

                frag1_num_atoms=frag1_num_atoms,

                frag2_num_atoms=frag2_num_atoms,

                complex_num_atoms=complex_num_atoms,

                max_num_neighbors=max_num_neighbors,

                neighbor_cutoff=neighbor_cutoff)

        if featurizer == "atomic_conv":

            featurizer = AtomicConvFeaturizer(

                labels=labels,

                frag1_num_atoms=frag1_num_atoms,

                neighbor_cutoff=neighbor_cutoff,

                max_num_neighbors=max_num_neighbors,

                batch_size=64)

    else:

        raise ValueError("Featurizer not supported")

  print("Featurizing Complexes")

  features, failures = featurizer.featurize_complexes(ligand_files,

                                                      protein_files)