class_docstr: Parameters
  ---------
  country_group : h5py.Group
      The group for a single country in an HDF5 daily pricing file.
class_docstr_tok: ["Parameters","--","--","--","--","-","country_group",":","h5py.Group","The","group","for","a","single","country","in","an","HDF5","daily","pricing","file","."]
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.
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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.
      """
      self._validate_assets([sid])
      self._validate_timestamp(dt)
  
      sid_ix = self.sids.searchsorted(sid)
      dt_ix = self.dates.searchsorted(dt.asm8)
  
      value = self._postprocessors[field](
          self._country_group[DATA][field][sid_ix, dt_ix]
      )
  
      # When the value is nan, this dt may be outside the asset's lifetime.
      # If that's the case, the proper NoDataOnDate exception is raised.
      # Otherwise (when there's just a hole in the middle of the data), the
      # nan is returned.
      if np.isnan(value):
          if dt.asm8 < self.asset_start_dates[sid_ix]:
              raise NoDataBeforeDate()
  
          if dt.asm8 > self.asset_end_dates[sid_ix]:
              raise NoDataAfterDate()
  
      return value
  
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 20 for calling the HDF5DailyBarReader obj's underlying member method code with example usage: obj.get_value(sid, dt, field) and returns: value