def allChunks(self):
        """Iterates over (xPos, zPos) tuples, one for each chunk in the level.
        May initiate a costly chunk scan."""
        if self._allChunks is None:
            self.preloadChunkPositions()
        return self._allChunks.__iter__()
Iterates over (xPos, zPos) tuples, one for each chunk in the level.
        May initiate a costly chunk scan.
pymclevel/infiniteworld.py