How to dump a dict to a JSON file?

I have a dict like this:

sample = {'ObjectInterpolator': 1629,  'PointInterpolator': 1675, 'RectangleInterpolator': 2042}

I can't figure out how to dump the dict to a JSON file as showed below:

{      
    "name": "interpolator",
    "children": [
      {"name": "ObjectInterpolator", "size": 1629},
      {"name": "PointInterpolator", "size": 1675},
      {"name": "RectangleInterpolator", "size": 2042}
     ]
}

Is there a pythonic way to do this?

You may guess that I want to generate a d3 treemap.

Solution 1:

import json
with open('result.json', 'w') as fp:
    json.dump(sample, fp)

This is an easier way to do it.

In the second line of code the file result.json gets created and opened as the variable fp.

In the third line your dict sample gets written into the result.json!

Solution 2:

Combine the answer of @mgilson and @gnibbler, I found what I need was this:

d = {"name":"interpolator",
     "children":[{'name':key,"size":value} for key,value in sample.items()]}
j = json.dumps(d, indent=4)
f = open('sample.json', 'w')
print >> f, j
f.close()

It this way, I got a pretty-print json file. The tricks print >> f, j is found from here: http://www.anthonydebarros.com/2012/03/11/generate-json-from-sql-using-python/