Feed the describejson.py script some JSON on stdin and it will print a
concise summary of the structure of the JSON.
The only option is --strictness to determine how strictly JSON objects
and lists should be compared. In order of increasing strictness, the
possible values are:
type: compare everything by type only.length: compare lists and objects by length.keys: compare lists by equality, objects by keys.equal: compare objects and list by equality.
Strictness affects the amount of output you'll see. For example if a list
contains two lists, describejson.py will just tell you that very
concisely if you use --strictness type. If you want the fact that things
differ in length or contents, use a higher strictness level.
You can see some examples of the script in use in this blog post: http://blogs.fluidinfo.com/terry/2012/08/09/describejson-a-python-script-for-summarizing-json-structure/
The output could probably be more verbose / helpful in some cases, but it's a difficult thing to get right, and the point is to produce a small summary omitting as much detail as possible.
Here's an example summarizing a 24M JSON file:
$ python describejson.py < sample.json
1 dict of length 3. Values:
1 int
1 dict of length 4. Values:
1 list of length 17993. Values:
17993 dicts of length 5. Values:
1 unicode
1 int
1 list of length 0.
2 unicodes
1 list of length 0.
1 list of length 11907. Values:
11907 dicts of length 5. Values:
1 unicode
1 int
1 list of length 1. Values:
1 unicode
2 unicodes
1 list of length 28068. Values:
28068 dicts of length 5. Values:
1 unicode
1 int
1 list of length 0.
2 unicodes
1 unicode
That's a 24 line summary of a 24M JSON file :-) Looking at the same file
with python -m json.tool produces almost half a million lines of output.
Terry Jones (terry@fluidinfo.com)
Aug 9, 2012