On Thu, Jan 30, 2014 at 11:05 PM, Dave Angel <da...@davea.name> wrote: > The finally has to happen before any return inside the try or the > except. And once you're in the finally clause you'll finish it > before resuming the except clause. Since it has a return, that > will happen before the other returns. The one in the except block > will never get reached. > > It's the only reasonable behavior., to my mind.
It's arguable that putting a return inside a finally is unreasonable behaviour, but that's up to the programmer. A finally clause can be used to do what might be done in C++ with a destructor: "no matter how this function/block exits, do this as you unwind the stack". In C++, I might open a file like this: void func() { ofstream output("output.txt"); // do a whole lot of stuff ... // at the close brace, output.~output() will be called, which will close the file } In Python, the equivalent would be: def func(): try: output = open("output.txt", "w") # do a whole lot of stuff ... finally: output.close() (Actually, the Python equivalent would be to use a 'with' clause for brevity, but 'with' uses try/finally under the covers, so it comes to the same thing.) The concept of the finally clause is: "Whether execution runs off the end, hits a return statement, or throws an exception, I need you do this before anything else happens". Having a return statement inside 'finally' as well as in 'try' is a bit of a corner case, since you're now saying "Before you finish this function and return something, I need you to return something else", which doesn't usually make sense. If you think Python's behaviour is confusing, first figure out what you would expect to happen in this situation :) ChrisA -- https://mail.python.org/mailman/listinfo/python-list