>>> a, b = [], [] >>> a.append(b) >>> b.append(a) >>> b in a True >>> a in a Traceback (most recent call last): File "<stdin>", line 1, in <module> RuntimeError: maximum recursion depth exceeded in cmp >>> >>> a is a[0] False >>> a == a[0] Traceback (most recent call last): File "<stdin>", line 1, in <module> RuntimeError: maximum recursion depth exceeded in cmp
---------- I'm a little new to this language so my mental model on whats going on may need to be refined. I expect "a in a" to evaluate to "False". Since it does not it may be that while checking equality it uses "==" and not "is". If that is the reason then the question becomes why doesn't "a == a[0]" evaluate to "False"? As a side, and if that is the reason, is there a version of "in" that uses "is"? "a is in a" does not work. Thankx, Trivik -- http://mail.python.org/mailman/listinfo/python-list
