On Sun, Mar 15, 2009, Michael Foord wrote:
Note that using exceptions for control flow can be bad for other implementations of Python. For example exceptions on the .NET framework are very expensive. (Although there are workarounds such as not really raising the exception - but they're ugly).
Isn't it better practise for exceptions to be used for exceptional circumstances rather than for control flow?
It seems to me that we as a development community already made a decision when we switched to StopIteration as the primary mechanism for halting ``for`` loops. (Not that it was really a new decision because parts of the Python community have always advocated using exceptions for control flow, but the ``for`` loop enshrines it.) I doubt that using exceptions for control flow in ``with`` blocks will cause anywhere near so much a performance degradation. -- Aahz (aahz@pythoncraft.com) <*> http://www.pythoncraft.com/ Adopt A Process -- stop killing all your children!