class_docstr: Custom ast walker. Parsers of other engines should subclass this class
  if necessary.
  
  Parameters
  ----------
  env : Scope
  engine : str
  parser : str
  preparser : callable
class_docstr_tok: ["Custom","ast","walker",".","Parsers","of","other","engines","should","subclass","this","class","if","necessary",".","Parameters","--","--","--","--","--","env",":","Scope","engine",":","str","parser",":","str","preparser",":","callable"]
code: def visit_NameConstant(self, node, **kwargs) -> Term:
      return self.const_type(node.value, self.env)
  
imports: from __future__ import annotations
  import ast
  from functools import partial, reduce
  from keyword import iskeyword
  import tokenize
  from typing import Callable, ClassVar, TypeVar
  import numpy
  from pandas.errors import UndefinedVariableError
  import pandas.core.common
  from pandas.core.computation.ops import ARITH_OPS_SYMS, BOOL_OPS_SYMS, CMP_OPS_SYMS, LOCAL_TAG, MATHOPS, REDUCTIONS, UNARY_OPS_SYMS, BinOp, Constant, Div, FuncNode, Op, Term, UnaryOp, is_term
  from pandas.core.computation.parsing import clean_backtick_quoted_toks, tokenize_string
  from pandas.core.computation.scope import Scope
  from pandas.io.formats import printing
label_desc: Use image node_id 14 for calling the BaseExprVisitor obj's underlying member method code with example usage: obj.visit_NameConstant(node) and returns: self