code: def generate_delta_data(frame, fdict, prefix1, prefix2):
      r"""Subtract two similar columns to get the delta value.
  
      Parameters
      ----------
      frame : pandas.DataFrame
          The input model frame.
      fdict : dict
          A dictionary of column names (key) and data types (value).
      prefix1 : str
          The prefix of the first team.
      prefix2 : str
          The prefix of the second team.
  
      Returns
      -------
      frame : pandas.DataFrame
          The completed dataframe with the delta data.
  
      """
      for key, value in list(fdict.items()):
          newkey = PSEP.join(["delta", key])
          key1 = PSEP.join([prefix1, key])
          key2 = PSEP.join([prefix2, key])
          frame[newkey] = frame[key1] - frame[key2]
      return frame
  
imports: import warnings
  from alphapy.__main__ import main_pipeline
  from alphapy.frame import read_frame
  from alphapy.frame import write_frame
  from alphapy.globals import ModelType
  from alphapy.globals import Partition, datasets
  from alphapy.globals import PSEP, SSEP, USEP
  from alphapy.globals import WILDCARD
  from alphapy.model import get_model_config
  from alphapy.model import Model
  from alphapy.space import Space
  from alphapy.utilities import valid_date
  import argparse
  import datetime
  from itertools import groupby
  import logging
  import math
  import numpy
  import os
  import pandas
  import sys
  import yaml
label_desc: Use image node_id 13 for calling a global function with example usage: generate_delta_data(frame, fdict, prefix1, prefix2) and returns: frame