Modifying JSON key values in Python

Question

I am trying to load a JSON file and change specific key values then save the updated entries to a new file. This JSON file has many entries with the same format. This is my furthest attempt before coming here, however it does not save the new values.

What am I missing?

#!/usr/bin/python
import simplejson as json
import names

in_file = open('Names.json', 'r')
out_file = open('Names_new.json','w')

data_file = in_file.read()
data = json.loads(data_file)

for x in data:
    nickname = x['nickname']
    newname = names.get_first_name()    
    nickname = newname

out_file.write(json.dumps(data))
out_file.close()

Patrick Yu · Accepted Answer · 2015-11-08 07:31:10Z

2

The problem is that you didn't change x['nickname'] when you wanted to assign newname to it. Instead, you only modified the variable nickname.

Try assigning the x['nickname'] directly:

for x in data:
    x['nickname'] = names.get_first_name()

edited Nov 8, 2015 at 7:31

Patrick Yu

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answered Nov 8, 2015 at 6:10

GhitaB

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Patrick Yu · Accepted Answer · 2015-11-08 06:44:45Z

2

You are just dumping old JSON data again into a new file without modifying its contents.

Instead, you should change the contents of the file with newname:

#!/usr/bin/python
import simplejson as json
import names

in_file = open('Names.json', 'r')
out_file = open('Names_new.json','w')

data_file = in_file.read()
data = json.loads(data_file)

for x in data:
    newname = names.get_first_name()    
    x['nickname'] = newname

out_file.write(json.dumps(data))
out_file.close()

edited Nov 8, 2015 at 6:44

Patrick Yu

9721 gold badge7 silver badges19 bronze badges

answered Nov 8, 2015 at 6:11

Harwee

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