def __init__(self, table_file):
        self.table_file = table_file
        
        # Read the pointer to the directory
        dirpos = table_file.read_ulong()
        # Read the pointer to the postings (0 if there are no postings)
        self.postpos = table_file.read_ulong()
        
        # Seek to where the directory begins and read it
        table_file.seek(dirpos)
        self.blockindex = table_file.read_pickle()
        self.blockcount = len(self.blockindex)
        self.blockpositions = table_file.read_array("L", self.blockcount)
        options = table_file.read_pickle()
        self.__dict__.update(options)
        
        if 0 > self.compressed and not has_zlib:
            raise Exception("zlib is not available: cannot decompress table")
        
        # Initialize cached block
        self.currentblock = None
        self.itemlist = None
        self.itemdict = None
        
        if self.haspostings:
            if self.stringids:
                self._read_id = self._read_id_string
            else:
                self._read_id = self._read_id_varint
            self.get = self._get_ignore_postinfo
        else:
            self.get = self._get_plain
dataset/ETHPy150Open tallstreet/Whoosh-AppEngine/src/whoosh/tables.py/TableReader.__init__/swapped operands of `>`