Edit data into JSON with Python

Question

I have a simple JSON

{
    "users":[
        {
          "last result": "2%",
          "login": "user",
          "password": "1",
          "id": "1"
        }
            ]
}

I want to add new user and then delete user by ID.

for example:

i want to add this:

{"id":"2", "login": "admin", "password":"22", "last result": "10%"}

after my action, json should look like this:

{
    "users":[
        {
          "last result": "2%",
          "login": "1user",
          "password": "1",
          "id": "2"
        },
        {
          "id":"2", 
          "login": "admin", 
          "password":"22", 
           "last result": "10%"
        }
            ]
}

I've tried this:

...
user = {"id": 2, "login": "admin", "password": "1", "last result": "2%"}
def save_data_to_json(user):
    jsonFile = open("auth.json", "r+")
    data = json.load(jsonFile)
    jsonFile.close()
    data["users"] = user
    jsonFile = open("auth.json", "a+")
    jsonFile.write(json.dumps(data))
    jsonFile.close()

But after this, my JSON looks a little bit strange:

{
    "users":[
        {
          "last result": "2%",
          "login": "1user",
          "password": "1",
          "id": "2"
        }
            ]
}{"users": {"id": 2, "login": "1user", "password": "1", "last result": "2%"}}

tohava · Accepted Answer · 2014-08-05 10:35:51Z

2

You should open auth.json with w and not with a+. When you open with a+ it means you append your output to it instead of overwriting it.

answered Aug 5, 2014 at 10:35

tohava

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Comments

NPatel · Accepted Answer · 2014-08-05 10:41:17Z

0

Try this code

import json
user = {"id": 2, "login": "admin", "password": "1", "last result": "2%"}
def save_data_to_json(user):
    jsonFile = open("/tmp/auth.json", "r+")
    data = json.load(jsonFile)
    jsonFile.close()
    data["users"].append(user)
    jsonFile = open("/tmp/auth.json", "w")
    jsonFile.write(json.dumps(data))
    jsonFile.close()

save_data_to_json(user)

answered Aug 5, 2014 at 10:41

NPatel

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Comments

Burhan Khalid · Accepted Answer · 2014-08-05 10:47:33Z

Your json object is has a key 'users' which is a collection of user objects. In your code though, you are doing data['users'] = user which is just replacing the existing collection with your new user, not adding to it:

>>> s = '''{
...     "users":[
...         {
...           "last result": "2%",
...           "login": "user",
...           "password": "1",
...           "id": "1"
...         }
...             ]
... }'''
>>> o = json.loads(s)
>>> o['users']
[{u'last result': u'2%', u'login': u'user', u'password': u'1', u'id': u'1'}]
>>> user = {"id": 2, "login": "admin", "password": "1", "last result": "2%"}
>>> o['users'] = user
>>> o['users']
{'last result': '2%', 'login': 'admin', 'password': '1', 'id': 2}

Note now how the object has changed. Instead of it being a collection of users, its now just one user object. This will have an impact on whatever application is reading this file.

Instead you need to do this:

>>> o['users'].append(user)
>>> o['users']
[{u'last result': u'2%', u'login': u'user', u'password': u'1', u'id': u'1'}, {'last result': '2%', 'login': 'admin', 'password': '1', 'id': 2}]

Now you have two users in the 'users' collection, to delete a user by their value:

>>> o['users'] = [u for u in o['users'] if u['login'] != 'admin']  # Get rid of the admin
>>> o['users']
[{u'last result': u'2%', u'login': u'user', u'password': u'1', u'id': u'1'}]

Then you can convert the object back to json and write it out.

Putting all this together, your code is:

with open('auth.json', 'r') as f:
    data = json.load(f)

data['users'].append(user)
# If you want to delete
data['users'] = [u for u in o['users'] if u['login'] != 'admin']  # Get rid of the admin

# Write it back

with open('auth.json', 'w') as f:
    json.dump(data, f)

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