[BioPython] Trying to transcribe RNA = error?

[Peter]

Now that the latest release is out, I wanted to return to a point
raised by Sebastian Bassi last month:

Do people agree that the Bio.Seq.transcibe() method should reject RNA sequences?

We already reject Seq objects with a protein alphabet.  I want to
accept Seq objects with a generic or nucleotide alphabet, and
sequences with a DNA alphabet are of course fine, but I had been on
the fence about trying to (re)transcribe RNA.

Unless anyone speaks up, I will side with Sebastian and add a check to
the  Bio.Seq.transcibe() method to reject RNA sequences, and a similar
check on the Bio.Seq.back_transcibe() method to reject DNA sequences.

Peter