'Return a string representation or raise a KeyError.'

def get_string(self, key, from_=False):

    (start, stop) = self._lookup(key)
    self._file.seek(start)
    if (not from_):
        self._file.readline()
    string = self._file.read((stop - self._file.tell()))
    return string.replace(os.linesep, '\n')
