Modified comment on one_hot according to Peter's suggestion

class OneHotFeaturizer(Featurizer):

  """Encodes SMILES or any arbitrary string as a one-hot array.

  """Encodes any arbitrary string or molecule as a one-hot array.

  This featurizer encodes either a SMILES string or any arbitrary string as a one-hot array.

  This featurizer encodes the characters within any given string as a one-hot 

  array. It also works with RDKit molecules: it can convert RDKit molecules to 

  SMILES strings and then one-hot encode the characters in said strings.

  Note

  ----

  This class needs RDKit to be installed in order to work with RDKit molecules.

  It does not need RDKit to be installed to work with arbitrary strings.

  """

  def __init__(self, charset: List[str] = ZINC_CHARSET, max_length: int = 100):