ocrd_utils.make_file_id: python 3.5 compat fix
@@ -831,6 +831,6 @@ def make_file_id(ocrd_file, output_file_grp, n):
if ret == ocrd_file.ID:
m = re.match(r'.*?(\d{3,}).*', ret)
if m:
- n = m[1]
+ n = m.group(1)
ret = concat_padded(output_file_grp, n)
return ret
