@cpelley beware of this kind of assignment ...
```
>>> from collections import namedtuple
>>> T = namedtuple('T', 'd')
>>> d = dict(one=1)
>>> d
{'one': 1}
>>> t = T(d)
>>> t
T(d={'one': 1})
>>> d['two'] = 2
>>> d
{'two': 2, 'one': 1}
>>> t
T(d={'two': 2, 'one': 1})
>>> 
```
You might want to do a copy here before you cause a riot ...