Python: Created nested dictionary from list of paths
- by sberry2A
I have a list of tuples the looks similar to this (simplified here, there are over 14,000 of these tuples with more complicated paths than Obj.part)
[ (Obj1.part1, {<SPEC>}), (Obj1.partN, {<SPEC>}), (ObjK.partN, {<SPEC>}) ]
Where Obj goes from 1 - 1000, part from 0 - 2000. These "keys" all have a dictionary of specs associated with them which act as a lookup reference for inspecting another binary file. The specs dict contains information such as the bit offset, bit size, and C type of the data pointed to by the path ObjK.partN.
For example: Obj4.part500 might have this spec, {'size':32, 'offset':128, 'type':'int'} which would let me know that to access Obj4.part500 in the binary file I must unpack 32 bits from offset 128.
So, now I want to take my list of strings and create a nested dictionary which in the simplified case will look like this
data = { 'Obj1' : {'part1':{spec}, 'partN':{spec} },
'ObjK' : {'part1':{spec}, 'partN':{spec} }
}
To do this I am currently doing two things, 1. I am using a dotdict class to be able to use dot notation for dictionary get / set. That class looks like this:
class dotdict(dict):
def __getattr__(self, attr):
return self.get(attr, None)
__setattr__ = dict.__setitem__
__delattr__ = dict.__delitem__
The method for creating the nested "dotdict"s looks like this:
def addPath(self, spec, parts, base):
if len(parts) > 1:
item = base.setdefault(parts[0], dotdict())
self.addPath(spec, parts[1:], item)
else:
item = base.setdefault(parts[0], spec)
return base
Then I just do something like:
for path, spec in paths:
self.lookup = dotdict()
self.addPath(spec, path.split("."), self.lookup)
So, in the end
self.lookup.Obj4.part500 points to the spec.
Is there a better (more pythonic) way to do this?
