Patches item #1685642, was opened at 2007-03-22 00:25 Message generated for change (Comment added) made by gbrandl You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=305470&aid=1685642&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Bj�rn Lindqvist (sonderblade) Assigned to: Nobody/Anonymous (nobody) Summary: Add IllegalStateError Initial Comment: Java has an exception called IllegalStateException. It is very useful for signaling "what you did would have been OK, but right now I can't do it." Python does not have a counterpart, but I think it should. For example, if you have a Python RDBMS-binding and you call db.select() before calling db.connect() it could raise a IllegalStateError (or maybe a subclass of it) that says 'IllegalStateError: "Must be connected to perform queries"'. Or for another example, take the Thread.start() function. Currently, if you call myThread.start() twice it will raise an AssertionError. That's no good because the result is undefined if you run python with -O. See Bug #904498 and Patch #1676820 (Martin v. Löwis comment). IllegalStateError should fit perfectly here: >>> t = threading.Thread() >>> t.start() >>> t.start() Traceback (most recent call last): ... IllegalStateError: thread already started ---------------------------------------------------------------------- >Comment By: Georg Brandl (gbrandl) Date: 2007-03-23 18:41 Message: Logged In: YES user_id=849994 Originator: NO In principle this is a good idea -- currently there's no guideline what to raise in such a situation. Some libraries raise RuntimeError (probably a new exception should be made subclass thereof), some do assertions, some raise custom exceptions. However, for this to be a complete patch, you'd have to find all those places where IllegalStateError would be appropriate. Also, switching to it would be a Py3k thing, provided that this breakage is suffered by python-dev. In any case, I think you should bring it up on the python-3000 mailing list -- otherwise this will never be decided upon. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=305470&aid=1685642&group_id=5470
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