class_docstr: Grover Atom Vocabulary Tokenizer
  
  The Grover Atom vocab tokenizer is used for tokenizing an atom using a
  vocabulary generated by GroverAtomVocabularyBuilder.
  
  Example
  -------
  >>> import tempfile
  >>> import deepchem as dc
  >>> from deepchem.feat.vocabulary_builders.grover_vocab import GroverAtomVocabularyBuilder
  >>> file = tempfile.NamedTemporaryFile()
  >>> dataset = dc.data.NumpyDataset(X=[['CC(=O)C'], ['CCC']])
  >>> vocab = GroverAtomVocabularyBuilder()
  >>> vocab.build(dataset)
  >>> vocab.save(file.name)  # build and save the vocabulary
  >>> atom_tokenizer = GroverAtomVocabTokenizer(file.name)
  >>> mol = Chem.MolFromSmiles('CC(=O)C')
  >>> atom_tokenizer.featurize([(mol, mol.GetAtomWithIdx(0))])[0]
  2
  
  Parameters
  ----------
  fname: str
      Filename of vocabulary generated by GroverAtomVocabularyBuilder
class_docstr_tok: ["Grover","Atom","Vocabulary","Tokenizer","The","Grover","Atom","vocab","tokenizer","is","used","for","tokenizing","an","atom","using","a","vocabulary","generated","by","GroverAtomVocabularyBuilder",".","Example","--","--","--","-",">",">",">","import","tempfile",">",">",">","import","deepchem","as","dc",">",">",">","from","deepchem.feat.vocabulary_builders.grover_vocab","import","GroverAtomVocabularyBuilder",">",">",">","file","=","tempfile.NamedTemporaryFile","(",")",">",">",">","dataset","=","dc.data.NumpyDataset","(","X=","[","[","'CC","(","=O",")","C","'","]",",","[","'CCC","'","]","]",")",">",">",">","vocab","=","GroverAtomVocabularyBuilder","(",")",">",">",">","vocab.build","(","dataset",")",">",">",">","vocab.save","(","file.name",")","#","build","and","save","the","vocabulary",">",">",">","atom_tokenizer","=","GroverAtomVocabTokenizer","(","file.name",")",">",">",">","mol","=","Chem.MolFromSmiles","(","'CC","(","=O",")","C","'",")",">",">",">","atom_tokenizer.featurize","(","[","(","mol",",","mol.GetAtomWithIdx","(","0",")",")","]",")","[","0","]","2","Parameters","--","--","--","--","--","fname",":","str","Filename","of","vocabulary","generated","by","GroverAtomVocabularyBuilder"]
code: def __init__(self, fname: str):
      self.vocabulary = GroverAtomVocabularyBuilder.load(fname)
  
imports: import json
  import logging
  import numpy
  import pandas
  from typing import Dict, Optional
  from collections import Counter
  from rdkit import Chem
  from deepchem.data import Dataset
  from deepchem.feat.base_classes import Featurizer
  from deepchem.utils.typing import RDKitMol, RDKitAtom, RDKitBond
  from deepchem.feat.vocabulary_builders.vocabulary_builder import VocabularyBuilder
label_desc: Use image node_id 1 to create a new GroverAtomVocabTokenizer object from inherited base classes: Featurizer with example: obj = GroverAtomVocabTokenizer(fname)