[FIXED] Diff json files and write changes

Issue

Using python I'm trying to diff two json files, update if there's a difference.

I have a rough draft going but haven't found out how to update my file!

import json
import sys
import jsondiff as jd
from jsondiff import diff


one="$1"
two="$2"

def compare_json(one, two) :

    with open(one, "r") as f, open(two, "r") as f2:
        file_one=json.load(f)
        file_two=json.load(f2)
        differences = diff(file_one, file_two, syntax='explicit')
        print(differences)
        update = differences[jd.update]
        print(update)
        insert = differences[jd.insert]
        print(insert)
        delete = differences[jd.delete]
        print(delete)

if __name__ == "__main__":
   compare_json(sys.argv[1],sys.argv[2])

I can get the differences but I haven't figure out a good way in updating the file.

My end goal is this:

diffy = diff(file_one,file_two)
if diffy
    update file_two

I only want to update values that are different in file two.

For example:

file one:

{ "type": "secure"
  "secure": {
    "id": "123",
    "client": "google"
  }
}

file two:

{ "type": "secure"
  "secure": {
    "id": "456",
    "client": "google"
  }
}

So the only difference between the files is the value of secure["id"]. I would like to update the value of secure["id"] in file two to the value of secure["id"] in file one. (Basically making file one equal to file two without rewriting everything in the file)

Any suggestions how to do this cleanly?

Solution

Sorry for the late response.. deadlines at work...

I ended up going with jsondiff

Here's a sample code snippet (without any exception handling):

   import jsondiff as jd
   from jsondiff import diff
   
   # open and load files
   with open(one, "r") as f, open(two, "r") as f2:
       file_one = json.load(f)
       file_two = json.load(f2)
       
       # get differences in file_two (file_one being the master)  
       differences = (file_two, file_one)
       
       # in order to access $update from differences use jd.update
       update = differences[jd.update]
       
       # assuming there are updates, loop through and update them accordingly
       for x in update:
           file_two.update({x : update[x]})

       
       # Open a new file and write the updated contents of file_two 
       outfile = open(outfile, "w")
       json.dump(file_two, outfile, indent=4)

Turns out it wasn't too bad once using jsondiff and understanding how to access the objects returned

Answered By - Stacker