(self, readers)
:param readers: a sequence of column reader objects.
:param readers: a sequence of column reader objects.
: param readers : a sequence of column reader objects .
def __init__(self, readers):
        """
        :param readers: a sequence of column reader objects.
        """

        self._readers = readers

        self._doc_offsets = []
        self._doccount = 0
        for r in readers:
            self._doc_offsets.append(self._doccount)
            self._doccount += len(r)
def __init__ ( self , readers ) : self . _readers = readers self . _doc_offsets = [ ] self . _doccount = 0 for r in readers : self . _doc_offsets . append ( self . _doccount ) self . _doccount += len ( r )