class_docstr: Helper class to determine properties from datatype strings.
class_docstr_tok: ["Helper","class","to","determine","properties","from","datatype","strings","."]
docstr: Extract the fold part of the datatype.
  
  :param datatype:
      parlai datatype
  
  :return: the fold
  
  >>> DatatypeHelper.fold("train:ordered")
  ... "train"
docstr_tok: ["Extract","the","fold","part","of","the","datatype",".",":","param","datatype",":","parlai","datatype",":","return",":","the","fold",">",">",">","DatatypeHelper.fold","(","``","train",":","ordered","''",")","...","``","train","''"]
code: def fold(cls, datatype: str) -> str:
      """
      Extract the fold part of the datatype.
  
      :param datatype:
          parlai datatype
  
      :return: the fold
  
      >>> DatatypeHelper.fold("train:ordered")
      ... "train"
      """
      return datatype.split(":")[0]
  
file_path: ParlAI/parlai/utils/data.py
imports: import random
  from typing import List
label_desc: Use image node_id 1 for calling the DatatypeHelper obj's underlying member method code with example usage: obj.fold(cls, datatype) and returns: datatype