class_docstr: Parameters
  ---------
  readers : dict[str -> SessionBarReader]
      A dict mapping country codes to SessionBarReader instances to
      service each country.
class_docstr_tok: ["Parameters","--","--","--","--","-","readers",":","dict","[","str","-",">","SessionBarReader","]","A","dict","mapping","country","codes","to","SessionBarReader","instances","to","service","each","country","."]
docstr: Retrieve the value at the given coordinates.
  
  Parameters
  ----------
  sid : int
      The asset identifier.
  dt : pd.Timestamp
      The timestamp for the desired data point.
  field : string
      The OHLVC name for the desired data point.
  
  Returns
  -------
  value : float|int
      The value at the given coordinates, ``float`` for OHLC, ``int``
      for 'volume'.
  
  Raises
  ------
  NoDataOnDate
      If the given dt is not a valid market minute (in minute mode) or
      session (in daily mode) according to this reader's tradingcalendar.
  NoDataForSid
      If the given sid is not valid.
docstr_tok: ["Retrieve","the","value","at","the","given","coordinates",".","Parameters","--","--","--","--","--","sid",":","int","The","asset","identifier",".","dt",":","pd.Timestamp","The","timestamp","for","the","desired","data","point",".","field",":","string","The","OHLVC","name","for","the","desired","data","point",".","Returns","--","--","--","-","value",":","float|int","The","value","at","the","given","coordinates",",","``","float","``","for","OHLC",",","``","int","``","for","'volume","'",".","Raises","--","--","--","NoDataOnDate","If","the","given","dt","is","not","a","valid","market","minute","(","in","minute","mode",")","or","session","(","in","daily","mode",")","according","to","this","reader","'s","tradingcalendar",".","NoDataForSid","If","the","given","sid","is","not","valid","."]
code: def get_value(self, sid, dt, field):
      """
      Retrieve the value at the given coordinates.
  
      Parameters
      ----------
      sid : int
          The asset identifier.
      dt : pd.Timestamp
          The timestamp for the desired data point.
      field : string
          The OHLVC name for the desired data point.
  
      Returns
      -------
      value : float|int
          The value at the given coordinates, ``float`` for OHLC, ``int``
          for 'volume'.
  
      Raises
      ------
      NoDataOnDate
          If the given dt is not a valid market minute (in minute mode) or
          session (in daily mode) according to this reader's tradingcalendar.
      NoDataForSid
          If the given sid is not valid.
      """
      try:
          country_code = self._country_code_for_assets([sid])
      except ValueError as exc:
          raise_from(
              NoDataForSid(
                  "Asset not contained in daily pricing file: {}".format(
                      sid
                  )
              ),
              exc,
          )
      return self._readers[country_code].get_value(sid, dt, field)
  
imports: from functools import partial
  import h5py
  import logbook
  import numpy
  import pandas
  from six import iteritems, raise_from, viewkeys
  from six.moves import reduce
  from zipline.data.bar_reader import NoDataAfterDate, NoDataBeforeDate, NoDataForSid, NoDataOnDate
  from zipline.data.session_bars import CurrencyAwareSessionBarReader
  from zipline.utils.memoize import lazyval
  from zipline.utils.numpy_utils import bytes_array_to_native_str_object_array
  from zipline.utils.pandas_utils import check_indexes_all_same
label_desc: Use image node_id 11 for calling the MultiCountryDailyBarReader obj's underlying member method code with example usage: obj.get_value(sid, dt, field) and returns: self