def clean_cxt(cxt: fca.Context,
min_att_extent: int = None,
min_att_len: int = None) -> fca.Context:
if (min_att_extent and min_att_extent > 1) or (min_att_len):
to_del = []
for att in cxt.attributes:
if ((min_att_extent and len(cxt.aprime([att])) < min_att_extent)
or (min_att_len and len(att) < min_att_len)):
to_del.append(att)
cxt.delete_attributes(to_del)
return cxt
