Python how to handle # in a dictionary

Question

I've got some json from last.fm's api which I've serialised into a dictionary using simplejson. A quick example of the basic structure is below.

{ "artist":
    "similar": { 
        "artist": {
            "name": "Blah",
            "image": [{"#text":"URLHERE","size": "small"},{"#text":"URLHERE","size":"medium"},{"#text":"URLHERE","size":"large"}]
         }
     }
}

Any ideas how I can access the image urls of various different sizes?

Thanks,
Jack

Answer 1

Python does not have any problem with # in strings used as dict keys.

>>> import json
>>> j = '{"#foo": 6}'
>>> print json.loads(j)
{u'#foo': 6}
>>> print json.loads(j)[u'#foo']
6
>>> print json.loads(j)['#foo']
6

There are, however, problems with the JSON you post. For one, it isn't valid (perhaps you're missing a couple commas?). For two, you have a JSON object with the same key "image" three times, which cannot coexist and do anything useful.

Answer 2

In Javascript, these two syntaxes are equivalent:

o.foo
o['foo']

In Python they are not. The first gives you the foo attribute, the second gives you the foo key. (It's debatable whether this was a good idea or not.) In Python, you wouldn't be able to access #text as:

o.#text

because the hash will start a comment, and you'll have a syntax error.

But you want

o['#text']

in any case.

Answer 3

You can get what you want from the image list with a list comprehension. Something like

desired = [x for x in images if minSize < x['size'] < maxSize]

Here, images would be the list of dicts from the inner level of you data structure.