def _read_next_bibcode(self, bibcode):
     """read all the info for the passed bibcode into a dict"""
     d = {}
     d['canonical'] = bibcode
     for x in data_files.keys():
         if x != 'canonical':
             v = self.readers[x].read_value_for(bibcode)
             d.update(v)
     return d
 def _close_all(self):
     for x in data_files.keys():
         if x in self.readers:
             self.readers[x].close()
             self.readers.pop(x)
 def _open_all(self):
     """open all input files"""
     self.readers = {}
     for x in data_files.keys():
         self.readers[x] = reader.NonbibFileReader(x, data_files[x])