get the nth prime number.

prime.py

import math

def prime(n):
    p = [2]
    x = 3
    while len(p) < n:
        isprime = True
        for i in p:
            if i > math.sqrt(x):
                break
            if x % i == 0:
                isprime = False
                break
        if isprime:
            p.append(x)
        x += 2
    return p[-1]

import time

s = time.time()
print prime(100000)
print time.time() - s