Converting a python dictionary to a JSON - like object

Question

I know this is going to sound like I just need to use json.loads from the title. But I don't think that's the case here. Or at least I should be able to do this without any libraries (plus I want to understand this and not just solve it with a library method).

What I have currently is a dictionary where the keys are words and the values are total counts for those words:

myDict = { "word1": 12, "word2": 18, "word3": 4, "word4": 45 }

and so on...

what I want is for it to become something like the following (so that I can insert it into a scraperwiki datastore):

myNewDict = {"entry": "word1", "count": 12, "entry": "word2", "count": 18, "entry": "word3", "count": 4, "entry": "word4", "count": 45}

I figured I could just loop over myDict and insert each key/value after my new chosen keys "entry" and "count" (like so):

for k, v in myDict.iteritems():
    myNewDict = { "entry": k, "count": v }

but with this, myNewDict is only saving the last result (so only giving me myNewDict={"entry":"word4", "total":45}

what am I missing here?

See stackoverflow.com/questions/3721357/… and stackoverflow.com/questions/7100125/storing-python-dictionaries — Mihai8
– Mihai8, Commented Apr 1, 2013 at 20:18
The keys on a dict (or a JSON object) must be unique, so the best you can do is a list of entry-count dicts, e.g. [{"entry":"word1", "count": 12},{"entry":"word2", ...}, ...] — Francis Avila
– Francis Avila, Commented Apr 1, 2013 at 20:28

Antoine Lassauzay · Accepted Answer · 2013-04-01 20:46:05Z

2

What you need is a list:

entries = []

for k, v in myDict.iteritems():
   entries.append({ "entry": k, "count": v })

Or even better with list comprehensions:

entries = [{'entry': k, 'count': v} for k, v in myDict.iteritems()]

In more details, you were overriding myDict at each iteration of the loop, creating a new dict every time. In case you need it, you could can add key/values to a dict like this :

myDict['key'] = ...

.. but used inside a loop, this would override the previous value associated to 'key', hence the use of a list. In the same manner, if you type:

myNewDict = {"entry": "word1", "count": 12, "entry": "word2", "count": 18, "entry": "word3", "count": 4, "entry": "word4", "count": 45}

you actually get {'count': 45, 'entry': 'word4'} !

Note: I don't know what's the expected format of the output data but JSON-wise, a list of dicts should be correct (in JSON keys are unique too I believe).

edited Apr 1, 2013 at 20:46

answered Apr 1, 2013 at 20:19

Antoine Lassauzay

1,60712 silver badges12 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Bryan Over a year ago

Don't forget about list comprehension [{'entry': k, 'count': v} for k, v in myDict.iteritems()]

martineau Over a year ago

An equally valid JSON-like object would be {'entries': [{k:v} for k, v in myDict.iteritems()]}.

ernie · Accepted Answer · 2013-04-01 20:38:27Z

0

While it's not clear 100% clear what output you want, if you want just a string in the format you've outlined above, you could modify your loop to be of the form:

myCustomFormat = '{'
for k, v in myDict.iteritems():
    myCustomFormat += '"entry": {0}, "count": {1},'.format(k, v)
# Use slice to trim off trailing comma
myCustomFormat = myCustomFormat[:-1] + '}'

That being said, this probably isn't what you want. As others have pointed out, the duplicative nature of the "keys" will make this somewhat difficult to parse.

answered Apr 1, 2013 at 20:38

ernie

6,37626 silver badges29 bronze badges

Collectives™ on Stack Overflow

Converting a python dictionary to a JSON - like object

2 Answers 2

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related