How to clear previous console output?

[Newgene]

Hi, group,
May I ask a newbie question?

Given the below example:

for i in range(100):
print "%s%%" % i

I want to show the progress by print 1% to 100%. But I hope  each
output will clear the previous output before print, so that I can see a
dynamic updated display of percentage, instead of print all percentages
one by one. How can I do that(what about on both windows and unix
platform)?

Thank you in advance for your expertise.

Best,

Cl