Python Script seen over Caleb's Shoulder in Deus Ex Machina

machina.py

# BlueBook code decryption

import sys

def sieve(n):
# Compute primes using sieve of Eratosthenes

        x = [1]*n
        x[1] = 0
    
        for i in range(2,n/2):
                j = 2*i
                while j < n:
                        x[j]=0
                        j = j+i
        return x

def prime(n,x):
# Find nth prime

        i = 1
        j = 1
        while j <= n:
                if x[i] == 1:
                        j = j + 1
                i = i + 1
        return i - 1
      
# Compute BlueBook unlock code

x = sieve(10000)

code = [1206,301,384,5]

key = [1,1,2,2,]

sys.stdout.write("".join(chr(i) for i in [73,83,66,78,32,61,32]))

for i in range (0,4):
    sys.stdout.write(str(prime(code[i],x)-key[i]))

print