datatable.options.display.max_nrows

A frame with more rows than this will be displayed truncated when the frame is printed to the console: only its first display.head_nrows and last display.tail_nrows rows will be printed. It is recommended to have head_nrows + tail_nrows <= max_nrows. Setting this option to None (or a negative value) will cause all rows in a frame to be printed, which may cause the console to become unresponsive.