Playing with dictionaries
David Eppstein
eppstein at ics.uci.edu
Mon Sep 22 13:57:52 EDT 2003
In article <10c662fe.0309220907.a84bea5 at posting.google.com>,
roberto at dealmeida.net (Roberto A. F. De Almeida) wrote:
> Suppose I have a dictionary containg nested dictionaries. Something
> like this:
>
> >>> pprint.pprint(dataset)
> {'casts': {'experimenter': None,
> 'location': {'latitude': None,
> 'longitude': None},
> 'time': None,
> 'xbt': {'depth': None,
> 'temperature': None}},
> 'catalog_number': None,
> 'z': {'array': {'z': None},
> 'maps': {'lat': None,
> 'lon': None}}}
>
> I want to assign to the values in the dictionary the hierarchy of keys
> to it. For example:
>
> >>> dataset['casts']['experimenter'] = 'casts.experimenter'
> >>> dataset['z']['array']['z'] = 'z.array.z'
>
> Of course I would like to do this automatically, independent of the
> structure of the dictionary. Is there an easy way to do it?
def makehierarchy(dataset,prefix=''):
for key in dataset:
if dataset[key] is None:
dataset[key] = prefix + key
elif isinstance(dataset[key], dict):
makehierarchy(dataset[key], prefix + key + ".")
else:
raise ValueError, "Unexpected data type in makehierarchy"
>>> makehierarchy(dataset,'dataset')
>>> pprint.pprint(dataset)
{'casts': {'experimenter': 'casts.experimenter',
'location': {'latitude': 'casts.location.latitude',
'longitude': 'casts.location.longitude'},
'time': 'casts.time',
'xbt': {'depth': 'casts.xbt.depth',
'temperature': 'casts.xbt.temperature'}},
'catalog_number': 'catalog_number',
'z': {'array': {'z': 'z.array.z'},
'maps': {'lat': 'z.maps.lat', 'lon': 'z.maps.lon'}}}
--
David Eppstein http://www.ics.uci.edu/~eppstein/
Univ. of California, Irvine, School of Information & Computer Science
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