python - How to remove whitespaces and newlines from every value in a JSON file?

Question

I have a JSON file that has the following structure:

{
    "name":[
        {
            "someKey": "

   some Value   "
        },
        {
            "someKey": "another value    "
        }
    ],
    "anotherName":[
        {
            "anArray": [
                {
                    "key": "    value

",
                    "anotherKey": "  value"
                },
                {
                    "key": "    value
",
                    "anotherKey": "value"
                }
            ]
        }
    ]
}

Now I want to strip off all he whitespaces and newlines for every value in the JSON file. Is there some way to iterate over each element of the dictionary and the nested dictionaries and lists?

Answer 1

Now I want to strip off all he whitespaces and newlines for every value in the JSON file

Using pkgutil.simplegeneric() to create a helper function get_items():

import json
import sys
from pkgutil import simplegeneric

@simplegeneric
def get_items(obj):
    while False: # no items, a scalar object
        yield None

@get_items.register(dict)
def _(obj):
    return obj.items() # json object. Edit: iteritems() was removed in Python 3

@get_items.register(list)
def _(obj):
    return enumerate(obj) # json array

def strip_whitespace(json_data):
    for key, value in get_items(json_data):
        if hasattr(value, 'strip'): # json string
            json_data[key] = value.strip()
        else:
            strip_whitespace(value) # recursive call


data = json.load(sys.stdin) # read json data from standard input
strip_whitespace(data)
json.dump(data, sys.stdout, indent=2)

Note: functools.singledispatch() function (Python 3.4+) would allow to use collections' MutableMapping/MutableSequence instead of dict/list here.

Output

{
  "anotherName": [
    {
      "anArray": [
        {
          "anotherKey": "value", 
          "key": "value"
        }, 
        {
          "anotherKey": "value", 
          "key": "value"
        }
      ]
    }
  ], 
  "name": [
    {
      "someKey": "some Value"
    }, 
    {
      "someKey": "another value"
    }
  ]
}