22 If there is a hierarchy of exceptions you can use the base class to catch all subclasses of exceptions. In the degenerate case you can catch all Java exceptions with:

How do I raise an exception in Python so that it can later be caught via an except block?

If you re-throw an exception within the catch block, and that exception is caught inside of another catch block, everything executes according to the documentation.

In the second scheme, if the promise p rejects, then the .catch() handler is called. If you return a normal value or a promise that eventually resolves from the .catch() handler (thus "handling" the error), then …

The subs used as examples are for readability only and explicitly for blackbox, unsafe actions, e.g. for IO or web connection like in the example. (I think this is the closest to an actual Try-Catch block you can …

throw; rethrows the original exception and preserves its original stack trace. throw ex; throws the original exception but resets the stack trace, destroying all stack trace information until your catch block. …

I recommend using catch(Exception ex) when you plan to reuse the exception variable only, and catch (alone) in other cases. Just a matter of style for the second use case, but if personally find it more …

I'm also not referring to using exceptions for flow control, this is clearly wrong in most cases. Those are important issues (some are more important), but not the focus here. How do try/catch blocks affect …

I think that this only works if you raise and then catch the exception, but not if you try getting the traceback before raising an exception object that you create, which you might want to do in some …

When I catch an exception, how do I get the type, file, and line number? Asked 16 years, 3 months ago Modified 1 year, 4 months ago Viewed 510k times