code: def _exists(self, key):
          
          filecache, keycache = self._fileslist()
          msg = keycache.get(key, None)
          if msg:
              path = msg.filename
              meta = filecache[path]
              return path, meta["hostname"], meta.get("flags", "")
          raise KeyError("not found %s" % key)
docs: Find a key in a particular section
  
          Searches through all the files and looks for matches with a regex.