[Biopython] GTF writing

[Brad Chapman]

Mic;

> What is necessary to change the following example
> http://biopython.org/wiki/GFF_Parsing#Writing_GFF3_from_scratch so the
> output would be GTF instead of GFF3?

Unfortunately, it doesn't support output to GTF. This was never a
priority because GTF is a underdefined format that GFF3 replaces, so
the goal was to move towards the current specification. Hope this helps,
Brad