You could easily provide your own random number generator, if you don't need cryptographic-strength random numbers.
EG: http://stromberg.dnsalias.org/svn/lcgrng/trunk/lcgrng.py That way you can be certain nothing else is using it. On Tue, Apr 15, 2014 at 8:54 AM, Nick Mellor <thebalance...@gmail.com> wrote: > Hi guys, > > (Python 2.7, Windows 7 64-bit) > > Here's a bit of code stress-testing a method addUpdate_special_to_cart. The > test adds and updates random "specials" (multiple products bundled at an > advantageous price) of various sizes to thousands of shopping carts, then > restocks the whole darn lot. The test passes if the stock level afterwards is > the same as it was before executing the code for all products. > > addUpdate_special_to_cart is working perfectly. But the test isn't. > > The test iterates over the same code twice, once with special_qty==4, once > with special_qty==0, reseeding the Python random module number generator to a > fixed seed (a string) between the iterations. special_qty==0 removes the > special and restocks the products. The test relies on precisely the same > random number sequence on both runs. > > Can you think of a reason why the random number generator should fall out of > sync between the two iterations? Because that's what's happening by the look > of it: occasionally products are returned to the wrong stockbin. No "random" > module method is used anywhere else while this code is executing. > > When I assign something non-random to the stockbin parameter, the test passes. > > Best wishes, > > > > Nick > > for qty in [4, 0]: > random.seed(seed) > for cart in range(test_size): > for special in range(randrange(3)): > s.addUpdate_special_to_cart(cart=cart, > stockbin=randrange(test_size), > > special_id=randrange(test_size), special_qty=qty, > > products=[(random.choice(PRODUCTS), random.choice(range(10))) > for r in > range(randrange(7))]) > -- > https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
