Prime Number Iterator

PrimeIter.py

def PrimeIter(num):                                                                                                                                                             
    seq = [ i for i in xrange(num) ]
                                                                                                                                            
    def gen():                                                                                                                                                                  
        for n in seq:                                                                                                                                                           
            if 2<=n<=num/2:                                                                                                                                            
                yield n                                                                                                                                                         
                                                                                                                                                                                
    for s in gen():                                                                                                                                                             
        for m in seq[s::s][1:]:                                                                                                                                                 
            seq[m] = 0
                                                                                                                                                          
    return ( r for r in seq if r!=0 and r>=2 )