Question

I am iterating a dict created using the following.

 tree = defaultdict(partial(defaultdict, partial(defaultdict, list)))
 for dt, hour, value in flat_list:
     tree[dt][hour]=[]
     tree[dt][hour].append(value)

My output looks like this:

 for k,v in tree.iteritems():
     2012-08-07 defaultdict(<functools.partial object at 0x1e0a050>, {'17': ['30']})
     2012-08-24 defaultdict(<functools.partial object at 0x1e0a050>, {'3': ['70']})

How do I get rid of this stuff? How do I iter like a regular dict?:

defaultdict(<functools.partial object at 0x1e0a050>

Answer 1

You are already iterating over the default dicts like a regular dict, but you are printing the defaultdict representation too.

To print these like you would print a regular dict, just turn them back into one:

 for k,v in tree.iteritems():
     print k, dict(v)

Note that a defaultdict is a direct subclass of dict, apart from the updated __getitem__ behaviour and the updated __repr__ hook¹, a defaultdict behaves exactly like a normal dict would, certainly when it comes to iterating.

^{1_{__copy__ and __deepcopy__ are overridden too, to create a new defaultdict when using the copy module. A custom __reduce__ is provided for the pickle module for the same reasons.}}