Explain & Annotate

molfp.explain

Bit-level explainability: map each ON bit to the atoms/bonds that triggered it.

For any molecule + fingerprint type, returns a dict mapping bit indices to the structural features responsible for setting that bit. This is the core novel feature of molfp — no other fingerprint library provides unified bit-level explanations across all fingerprint types.

explain(smiles_or_mol, fp_type)

Explain which atoms/bonds set each ON bit in a fingerprint.

Parameters:

Name	Type	Description	Default
smiles_or_mol	Union[str, Mol]	SMILES string or RDKit Mol	required
fp_type	str	fingerprint name (e.g. "ecfp4", "maccs", "substructure")	required

Returns:

Type	Description
dict[int, Any]	dict mapping bit_index → list of atom/bond explanations.
dict[int, Any]	Format varies by FP type: - ecfp4/atompairs2d: {bit: [(center_atom_idx, radius), ...]} - rdk/rdk_ext/rdk_graphonly: {bit: [[bond_indices], ...]} - substructure/klekota_roth: {bit: [atom_indices_tuple, ...]} - pubchem: {bit: {"section": str, "detail": str, "atoms": [...]}} - maccs: {bit: [atom_indices_tuple, ...]} - estate: {bit: [atom_idx, ...]}

molfp.annotate

Chemical annotation: human-readable names and descriptions for fingerprint bits.

annotate(fp_type, bit_idx)

Get human-readable annotation for a specific fingerprint bit.

Parameters:

Name	Type	Description	Default
fp_type	str	fingerprint name (e.g. "substructure", "pubchem", "maccs")	required
bit_idx	int	bit index (0-based)	required

Returns:

Type	Description
dict[str, Any]	dict with keys: name, smarts (if applicable), description, category

get_annotations(fp_type)

Get all annotations for a fingerprint type. Returns {bit_idx: annotation_dict}.