in compile_table.py [0:0]
def __flatten_dict(d, joiner="_"):
items = []
for k, v in d.items():
if type(v) is dict:
for k2, v2 in __flatten_dict(v, joiner=joiner):
items.append((k + joiner + k2, v2))
else:
items.append((k, v))
return items