On Aug 15, 11:38 am, Mark Lawrence <breamore...@yahoo.co.uk> wrote: > Dr. Phillip M. Feldman wrote:> I wrote the following correct but inefficient > test of primality for purposes > > of demonstrating that the simplest algorithm is often not the most > > efficient. But, when I try to run the following code with a value of n that > > is large enough to produce a significant amount of running time, I get an > > out-of-memory error! > > > def is_prime(n): > > for j in range(2,n): > > if (n % j) == 0: return False > > return True > > > It seems as though Python is actually expanding range(2,n) into a list of > > numbers, even though this is incredibly wasteful of memory. There should be > > a looping mechanism that generates the index variable values incrementally > > as they are needed. > > I have a strong suspicion that you will find hints in the Python > documentation that this has already been addressed. Perhaps you could > try reading before posting?
Alternative hypothesis: the good doctor read the Python 3.x documentation but absent-mindedly ran Python 2.x -- http://mail.python.org/mailman/listinfo/python-list
