class_docstr: PubChem Fingerprint.
  
  The PubChem fingerprint is a 881 bit structural key,
  which is used by PubChem for similarity searching.
  Please confirm the details in [1]_.
  
  References
  ----------
  .. [1] ftp://ftp.ncbi.nlm.nih.gov/pubchem/specifications/pubchem_fingerprints.pdf
  
  Note
  -----
  This class requires RDKit and PubChemPy to be installed.
  PubChemPy use REST API to get the fingerprint, so you need the internet access.
  
  Examples
  --------
  >>> import deepchem as dc
  >>> smiles = ['CCC']
  >>> featurizer = dc.feat.PubChemFingerprint()
  >>> features = featurizer.featurize(smiles)
  >>> type(features[0])
  <class 'numpy.ndarray'>
  >>> features[0].shape
  (881,)
docstr: Initialize this featurizer.
docstr_tok: ["Initialize","this","featurizer","."]
code: def __init__(self):
      """Initialize this featurizer."""
      try:
          from rdkit import Chem  # noqa
          import pubchempy as pcp  # noqa
      except ModuleNotFoundError:
          raise ImportError(
              "This class requires PubChemPy to be installed."
          )
  
      self.get_pubchem_compounds = pcp.get_compounds
  
imports: import numpy
  from deepchem.utils.typing import RDKitMol
  from deepchem.feat.base_classes import MolecularFeaturizer
label_desc: Use image node_id 1 to create a new PubChemFingerprint object from inherited base classes: MolecularFeaturizer with example: obj = PubChemFingerprint()