User:Ixo/Project/primes.py

# Example for pippy activity
# Finding those elusive primes
#  20080218, ixo on wiki.laptop.org

print "Prime numbers are only evenly divisible by 1 and itself."
print "How many prime numbers do you want (2 or more)?  100 "

print "1 2 ",

primes_found = 2
number = 3;

while primes_found < 100:

     limit_check = number/4;  # should be square_root
     check_factor = 2;
     factor_found = False

     while ((check_factor <= limit_check) and (not factor_found)):  
     	div = round(number / check_factor)
     	factor = div * check_factor;
        if factor == number:
            factor_found = True
        check_factor = check_factor + 1

     if not factor_found :
            primes_found = primes_found + 1
            print number,

     number = number + 1

print " .. done."