To get just what you need you could do:
```
from hookutils import collect_submodules
hiddenimports = []

for x in collect_submodules('reportlab.pdfbase'):
    if x.startswith('reportlab.pdfbase._fontdata_'):
        hiddenimports.append(x)
```
Could you please also add comment to the code what OS and that you tested it with Reportlab 2.7 and 3.0a1?

Thanks