code: def transform_candles_to_df(candles):
      return pd.DataFrame(candles).set_index("last_traded")
  
imports: import hashlib
  import json
  import os
  import pickle
  import shutil
  from datetime import date, datetime
  import pandas
  from catalyst.assets._assets import TradingPair
  from six import string_types
  from six.moves.urllib import request
  from catalyst.constants import DATE_FORMAT, SYMBOLS_URL
  from catalyst.exchange.exchange_errors import ExchangeSymbolsNotFound
  from catalyst.exchange.utils.serialization_utils import ExchangeJSONEncoder, ExchangeJSONDecoder
  from catalyst.utils.memoize import weak_lru_cache
  from catalyst.utils.paths import data_root, ensure_directory, last_modified_time
label_desc: Use image node_id 32 for calling a global function with example usage: transform_candles_to_df(candles) and returns: pd