CODEWITHSUNDEEP
pythonjsoncompare
ankith shetty
ankith shetty

Reputation: 13

Comparing two JSON files and update the modification

I'm working on a requirement where in I have to compare two json files (master.json and delta.json and update the object if there is any change for any of the key:value pair within the object in the master.json file

for e.g:

        **master.json**
       
        {
         [
           {
             host: abc
             IP  : 10.10.11.1
           }
           {
             host: def
             IP: 10.10.11.2
           }
          ]
         }

         **delta.json**
         {
          [ 
            {
             host: abc
             IP: 10.12.12.2
           }
          ]
         }

As in the example IP address for host changed in the delta.json..This update has to be moved to the master.json

Resulting master.json should be

       **master.json**
       
        {
         [
           {
             host: abc
             IP  : 10.12.12.2
           }
           {
             host: def
             IP: 10.10.11.2
           }
          ]
         }

Upvotes: 1

Views: 949

Answers (1)

Jesper Hustad
Jesper Hustad

Reputation: 352

Using the JSON module we can parse the json from a file. To update the master with the delta you can use a recursive function.

import json

master = json.loads(open("master.json", 'r', encoding='utf-8').read())
delta = json.loads(open("delta.json", 'r', encoding='utf-8').read())

def iterate_paralell(delta, master):
    for k,v in delta.items():

        # if it's another dict or list run recursively
        if isinstance(v, dict): iterate_paralell(v, master[k])
        elif isinstance(v, list):
            for i in range(len(v)): iterate_paralell(v[i], master[k][i])
        
        # update the maste with delta value
        else:        
            master[k] = v

iterate_paralell(delta, master)

The function iterates over the delta object and update the master when it reaches a "leaf" by passing it along as a parameter.

master.json

{
    "connections": [
        {
            "host": "abc",
            "IP": "10.10.11.1"
        },
        {
            "host": "def",
            "IP": "10.10.11.2"
        }
    ]
}

delta.json

{
    "connections": [
        {
            "host": "abc",
            "IP": "10.12.12.2"
        }
    ]
}

Upvotes: 2

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