Converting JSON into Python dict

Question

I've been searching around trying to find an answer to this question, and I can't seem to track it down. Maybe it's too late in the evening to figure the answer out, so I turn to the excellent readers here.

I have the following bit of JSON data that I am pulling out of a CouchDB record:

"{\"description\":\"fdsafsa\",\"order\":\"1\",\"place\":\"22 Plainsman Rd, Mississauga, ON, Canada\",\"lat\":43.5969175,\"lng\":-79.7248744,\"locationDate\":\"03/24/2010\"},{\"description\":\"sadfdsa\",\"order\":\"2\",\"place\":\"50 Dawnridge Trail, Brampton, ON, Canada\",\"lat\":43.7304774,\"lng\":-79.8055435,\"locationDate\":\"03/26/2010\"},"

This data is stored inside a Python dict under the key 'locations' in a dict called 'my_plan'. I want to covert this data from CouchDB into a Python dict so I can do the following in a Django template:

{% for location in my_plan.locations %}                                                           
<tr>
    <td>{{ location.place }}</td>
    <td>{{ location.locationDate }}</td>
</tr>

{% endfor %}

I've found lots of info on converting dicts to JSON, but nothing on going back the other way

Thanks in advance for the help!

Answer 1

django.utils.simplejson.loads(someJson)

Answer 2

The string you show is not a JSON-coded object (eqv to a Python dict) -- more like an array (eqv to a list) without brackets and with a stray extra comma at the end. So (using simplejson for version portability -- the stndard library's json in 2.6 is fine too of course!-):

>>> import simplejson                                                           >>> js = "{\"description\":\"fdsafsa\",\"order\":\"1\",\"place\":\"22 Plainsman Rd, Mississauga, ON, Canada\",\"lat\":43.5969175,\"lng\":-79.7248744,\"locationDate\":\"03/24/2010\"},{\"description\":\"sadfdsa\",\"order\":\"2\",\"place\":\"50 Dawnridge Trail, Brampton, ON, Canada\",\"lat\":43.7304774,\"lng\":-79.8055435,\"locationDate\":\"03/26/2010\"},"
>>> simplejson.loads('[%s]' % js[:-1])

[{'description': 'fdsafsa', 'order': '1', 'place': '22 Plainsman Rd, Mississauga, ON, Canada', 'lat': 43.596917500000004, 'lng': -79.724874400000004, 'locationDate': '03/24/2010'}, {'description': 'sadfdsa', 'order': '2', 'place': '50 Dawnridge Trail, Brampton, ON, Canada', 'lat': 43.730477399999998, 'lng': -79.805543499999999, 'locationDate': '03/26/2010'}]

If you really want a dict you'll have to specify how to treat these two unnamed items, i.e., what arbitrary keys you want to slap on them...?

Answer 3

• Use the json module for loading JSON. (Pre-2.6 use the third party simplejson module, which has the same exact API.)

  >>> import json
  >>> s = '{"foo": 6, "bar": [1, 2, 3]}'
  >>> d = json.loads(s)
  >>> print d
  {u'foo': 6, u'bar': [1, 2, 3]}
  

• Your actual data cannot be loaded this way since it's actually two JSON objects separated by a comma and with a trailing comma. You'll need to separate them or otherwise deal with this.

  • Where did you get this string?

Answer 4

This is not an answer to your question, but I've had enough grief with it that I'll point it out.

Be very careful with Unicode and JSON. All strings in JSON are in Unicode, and UTF-8 by default. Also, JSON's idea of Unicode and quoting might not be quite what you expect. Do extra testing, for the errors are subtle and fatal.