How to print out forty blank lines using the function clear_screen? [closed]

How to print out forty blank lines using the function clear_screen? [closed]

References

Reference NO 1

http://www.gnu.org/software/screen/manual/screen.html

Reference NO 2

http://docs.oracle.com/cd/B10501_01/server.920/a90842/ch7.htm

Reference NO 3

http://docs.python.org/library/turtle.html

Reference NO 4

http://www.openframeworks.cc/tutorials/introduction/001_chapter1.html

Reference NO 5

http://anh.cs.luc.edu/python/hands-on/handsonHtml/handson.html

Reference NO 6

http://support.sprint.com/global/pdf/user_guides/lg/optimus_g/optimus_g_by_lg_ug.pdf

Reference NO 7

http://cran.r-project.org/doc/contrib/Paradis-rdebuts_en.pdf

Reference NO 8

http://rsbweb.nih.gov/ij/developer/macro/functions.html