Can a multi-condition if-statement include an exception along with boolean/relational conditions?

I have a piece of code that fits each voxel in a data cube with a Gaussian plus a non-zero, sloping linear baseline. Each voxel is a spectrum of line+continuum emission that, depending on the location, can be pretty noisy and is known not to behave well at the edges of either the image or the spectral range. Therefore, sometimes it's necessary to fit the Gaussian and linear components separately in the parts of the spectra where each is most likely to occur, either because the original fit failed, or because the fitting parameters were nonsensical and I can see the line it failed to fit despite the noise. I'd skip straight to the piecewise version if I could, but the discontinuities can be problematic, not to mention it's generally a more costly procedure in terms of time and memory usage.

So my situation is this: I want to have my program respond to multiple possible conditions, where some are exceptions (ValueError and RuntimeError) and the others are Boolean or relational conditions, with the same procedure. Can that be done? Right now I have two copies of the same procedure, one in the exception block and the other in the else block with an internal if-statement, and it's annoying the heck out of me. If I can't combine them, is there a way to reroute one or the other statement to the same block of code without defining a new function?