In <e16d39fa-161b-409e-9b6b-0238ee262bbd at googlegroups.com> Shamefaced <manengstudent at gmail.com> writes: > else: > print("%8.3f %s: Waited too long %6.3f" % (now()/60, self.name, wait) + " time units have passed - Customer has left") > leavelist.append(self.acquired) What is self.acquired? Judging from earlier code it appears to be a function, but here you're appending it to leavelist. Did you really mean to append a function object to leavelist? -- John Gordon A is for Amy, who fell down the stairs gordon at panix.com B is for Basil, assaulted by bears -- Edward Gorey, "The Gashlycrumb Tinies"