How am I supposed to catch a custom exception when I cannot import `pyvisa-py` due to the minus sign in the package name?

Dear all,

sometimes I need to deal with exceptions which are raised by pyvisa-py, for example pyvisa-py.protocols.rpc.RPCError. I cannot catch this specific exception, since I need to import it, which is not possible since the package name contains a minus sign (not allowed in Python module/package names).

Maybe I am missing something obvious here, but I have no idea how this package should be used externally.

I could not find anything related in the visa or pyvisa package…

Thanks, Tom

[tamasgal]

It’s hard to reproduce… it happens during very long (>50 hours) data takings from time to time. I’ll try to get some useful information.

OK, I’ll go with importlib then. Still wondering why an invalid package names chosen initially…

[MatthieuDartiailh]

Indeed PyVisaLibrary.open should catch errors when creating sessions. Sessions should raise errors that makes it easy to provide the right kind of error messages. However we should catch all exceptions PyVisaLibrary.open and not-only the types we expect.

We also have to make sure that we preserve enough information to debug the error. If we cannot propagate a meaningful error message, we should at the very least log them.

I do not think we need to convert the rpc.RPCError to a bare Exception, using an except Exception clause will catch everything we can be interested in.