class_docstr: Object serving as a base class for all engines.
class_docstr_tok: ["Object","serving","as","a","base","class","for","all","engines","."]
docstr: Convert an expression for evaluation.
  
  Defaults to return the expression as a string.
docstr_tok: ["Convert","an","expression","for","evaluation",".","Defaults","to","return","the","expression","as","a","string","."]
code: def convert(self):
      """Convert an expression for evaluation.
  
      Defaults to return the expression as a string.
      """
      return printing.pprint_thing(self.expr)
  
imports: import abc
  from pandas.compat import map
  from pandas import compat
  from pandas.core.computation.align import _align, _reconstruct_object
  from pandas.core.computation.ops import UndefinedVariableError, _mathops, _reductions
  import pandas.io.formats.printing
label_desc: Use image node_id 2 for calling the AbstractEngine obj's underlying member method code with example usage: obj.convert() and returns: printing