Any way to get the composition from Proforma object?

[retronade]

I was going to calculate the isotopic distribution for all the precursors identified by DIA-NN. However, I can't work out how to obtain the composition from the Proforma peptide notation. While I can obtain the mass or m/z, Proforma is not a valid input for either mass.Composition or pyteomics.mass.mass.isotopologues. Consequently, I am struggling to utilise this helpful class/function. Is there a way to generate valid input for these from a Proforma object?

Thanks for writing this awesome library!

[retronade]

I've now parsed out the UniMod Id from the sequence, created a UniMod Object by Id and used the composition property to add to the stripped.sequence composition. So, I'm kind of fine now. But I would still be interessed if there is a more direct way.

[levitsky]

This is a great question and I think we are indeed lacking a direct way to calculate the total composition of a ProForma object. Depending on the way modifications are defined, it may not be possible to do, but having a method/property to attempt to do this sounds like a very reasonable expectation.