On 3/29/2012 3:28 AM, Ulrich Eckhardt wrote:
Equality comparison is by id. So this code will not do what you want.>>> Exception('foo') == Exception('foo') False Yikes! That was unexpected and completely changes my idea. Any clue whether this is intentional? Is identity the fallback when no equality is defined for two objects?
Yes. The Library Reference 4.3. Comparisons (for built-in classes) puts is this way. "Objects of different types, except different numeric types, never compare equal. Furthermore, some types (for example, function objects) support only a degenerate notion of comparison where any two objects of that type are unequal." In other words, 'a==b' is the same as 'a is b'. That is also the default for user-defined classes, but I am not sure where that is documented, if at all.
-- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
