code: def bcolz_exchange_daily_write_read(self, exchange_name):
      start = pd.to_datetime("2017-10-01 00:00")
      end = pd.to_datetime("today")
      freq = "daily"
  
      bundle = ExchangeBundle(exchange_name)
  
      df = self.generate_df(exchange_name, freq, start, end)
  
      print(df.index[0], df.index[-1])
  
      writer = BcolzExchangeBarWriter(
          rootdir=self.root_dir,
          start_session=df.index[0],
          end_session=df.index[-1],
          data_frequency=freq,
          write_metadata=True,
      )
  
      data = []
      data.append((1, df))
      writer.write(data)
  
      reader = BcolzExchangeBarReader(
          rootdir=self.root_dir, data_frequency=freq
      )
  
      arrays = reader.load_raw_arrays(
          self.columns,
          start,
          end,
          [
              1,
          ],
      )
  
      periods = bundle.get_calendar_periods_range(start, end, freq)
  
      dx = get_df_from_arrays(arrays, periods)
  
      assert_equals(df.equals(dx), True)
      pass
  
imports: import random
  import shutil
  import tempfile
  import pandas
  from nose.tools import assert_equals
  from catalyst.exchange.exchange_bcolz import BcolzExchangeBarWriter, BcolzExchangeBarReader
  from catalyst.exchange.exchange_bundle import ExchangeBundle
  from catalyst.exchange.utils.bundle_utils import get_df_from_arrays
label_desc: Use image node_id 9 for calling the TestBcolzWriter obj's underlying member method code with example usage: obj.bcolz_exchange_daily_write_read(exchange_name) without return types