class_docstr: An object to assist in building Vega-Lite Expressions
class_docstr_tok: ["An","object","to","assist","in","building","Vega-Lite","Expressions"]
code: def __getattr__(self, attr):
      if attr.startswith("__") and attr.endswith("__"):
          raise AttributeError(attr)
      return GetAttrExpression("datum", attr)
  
imports: from ..utils import SchemaBase
label_desc: Use image node_id 2 for calling the DatumType obj's underlying member method code with example usage: obj.__getattr__(attr) and returns: GetAttrExpression