Question

My app use QT for the gui layer, and many other lib I made.

One of this other lib is quite complex (it’s a type system) and full of asserts to make it as solid as possible.

But when an assert is triggered in this lib, the Qt mainloop simply continue.
I have a qt_debug() that works well (with pyqtRemoveInputHook) for the Qt part but nothing for the rest of python libraries.

And, obviously I would avoid to change code in the library as it should useable without Qt.

The best solution would be an assert hook, but despite googling around I didn’t any obvious way to do it. Any idea ?

Answer 1

Using assert is the wrong way. For one thing, if Python is run with -O (or -OO) asserts are turned off; for another, the error message is not very helpful. That library needs to be redesigned to properly use exceptions.

As far as using the library as it stands: what do you want to have happen? Should your app quit? If so, you could create your own AssertionError class, replace the one in __builtins__ with yours, and have it do whatever you want in its __init__. Note that you are completely on your own if you do this.