class_docstr: Defines a single training or test example.
  
  Stores each column of the example as an attribute.
code: def fromlist(cls, data, fields):
      ex = cls()
      for (name, field), val in zip(fields, data):
          if field is not None:
              if isinstance(val, str):
                  val = val.rstrip("\n")
              # Handle field tuples
              if isinstance(name, tuple):
                  for n, f in zip(name, field):
                      setattr(ex, n, f.preprocess(val))
              else:
                  setattr(ex, name, field.preprocess(val))
      return ex
  
file_path: pytext/pytext/legacy/data/example.py
imports: import json
  from functools import reduce
label_desc: Use image node_id 4 for calling the Example obj's underlying member method code with example usage: obj.fromlist(cls, data, fields) and returns: ex