code: def prepare_indices(
      cross, df_option_tot=None, df_option_tc=None, df_spot_tot=None
  ):
      df_list = []
  
      if df_option_tot is not None:
          df_list.append(
              pd.DataFrame(df_option_tot[cross + "-option-tot.close"])
          )
          df_list.append(
              pd.DataFrame(
                  df_option_tot[cross + "-option-delta-tot.close"]
              )
          )
          df_list.append(
              pd.DataFrame(
                  df_option_tot[cross + "-delta-pnl-index.close"]
              )
          )
  
      if df_option_tc is not None:
          df_list.append(
              pd.DataFrame(
                  df_option_tc[cross + "-option-tot-with-tc.close"]
              )
          )
          df_list.append(
              pd.DataFrame(
                  df_option_tc[
                      cross + "-option-delta-tot-with-tc.close"
                  ]
              )
          )
          df_list.append(
              pd.DataFrame(
                  df_option_tc[cross + "-delta-pnl-index-with-tc.close"]
              )
          )
  
      if df_spot_tot is not None:
          df_list.append(df_spot_tot)
  
      df = calculations.join(df_list, how="outer").fillna(
          method="ffill"
      )
  
      return calculations.create_mult_index_from_prices(df)
  
file_path: finmarketpy/finmarketpy_examples/fx_options_indices_examples.py
imports: import pandas
  from chartpy import Chart, Style
  from findatapy.market import Market, MarketDataGenerator, MarketDataRequest
  from findatapy.timeseries import Filter, Calculations, RetStats
  from findatapy.util.loggermanager import LoggerManager
  from finmarketpy.curve.fxoptionscurve import FXOptionsCurve
  from finmarketpy.curve.volatility.fxvolsurface import FXVolSurface
  from finmarketpy.curve.volatility.fxoptionspricer import FXOptionsPricer
label_desc: Use image node_id 1 for calling a global function with example usage: prepare_indices(cross, df_option_tot, df_option_tc, df_spot_tot) and returns: calculations