Random Prime Generator/Modular Arithmetic

[Tuvas]

I have made and recently posted a libary I made to do Modular
Arithmetic and Prime numbers on my website  at
http://www.geocities.com/brp13/Python/index.html . I am currently in a
crypotology class, and am working on building a RSA public key
cryptology system for a class project. I am building the librarys just
to get the experience to do so. However, I would ask if any of you know
of any gaping security holes that can easily be seen from my selection
of random prime numbers, ei, are they somehow predictable? Just wanting
to make sure. For simpler than going to the website, I used the ranint
function to pick a random prime number, then ran it through the miller
rabin primality test. It's a probabalistic test, which means it isn't
full proof, but there's still less than 1 in a million of giving a
false reading. Thanks! And if you should so want for some reason, feel
free to use it!