How can I find annotated proteins from high level GO terms?

Question

[mike.thon]

I have GO annotations for a non-model organism and I did an enrichment test using the goatools script find_enrichment.py. There does not seem to be a way to print a list of genes associated with the enriched GO terms. So, given a GO term, how can I make a list of all genes associated with all child terms? As input I have the gene_ontology obo file and my gene_association file.