code: def csv(ticker, path='data.csv', field='', mrefresh=False, **kwargs):
      
      # set defaults if not specified
      if 'index_col' not in kwargs:
          kwargs['index_col'] = 0
      if 'parse_dates' not in kwargs:
          kwargs['parse_dates'] = True
  
      # read in dataframe from csv file
      df = pd.read_csv(path, **kwargs)
  
      tf = ticker
      if field is not '' and field is not None:
          tf = '%s:%s' % (tf, field)
  
      # check that required column exists
      if tf not in df:
          raise ValueError('Ticker(field) not present in csv file!')
  
      return df[tf]
docs: Data provider wrapper around pandas' read_csv. Provides memoization.