Newbie question about memory management

[Oh Kyu Yoon]

I am writing my first python program, and I have to deal with several lists
of double precision numbers that are about 10,000,000 in length.
If I have 5 such lists, 5 x 10,000,000 x 8bytes ~ 400 MB which is too much
for the computer memory.
Does anyone have better strategies to do this?
Thanks.