bz2.py 文件源码

def readline(self, size=-1):
        """Read a line of uncompressed bytes from the file.

        The terminating newline (if present) is retained. If size is
        non-negative, no more than size bytes will be read (in which
        case the line may be incomplete). Returns b'' if already at EOF.
        """
        if not isinstance(size, int):
            if not hasattr(size, "__index__"):
                raise TypeError("Integer argument expected")
            size = size.__index__()
        with self._lock:
            self._check_can_read()
            # Shortcut for the common case - the whole line is in the buffer.
            if size < 0:
                end = self._buffer.find(b"\n", self._buffer_offset) + 1
                if end > 0:
                    line = self._buffer[self._buffer_offset : end]
                    self._buffer_offset = end
                    self._pos += len(line)
                    return line
            return io.BufferedIOBase.readline(self, size)