How to add a key-value to JSON data retrieved from a file?
Question:
I am new to Python and I am playing with JSON data. I would like to retrieve the JSON data from a file and add to that data a JSON key-value “on the fly”.
That is, my json_file
contains JSON data as-like the following:
{"key1": {"key1A": ["value1", "value2"], "key1B": {"key1B1": "value3"}}}
I would like to add the "ADDED_KEY": "ADDED_VALUE"
key-value part to the above data so to use the following JSON in my script:
{"ADDED_KEY": "ADDED_VALUE", "key1": {"key1A": ["value1", "value2"], "key1B": {"key1B1": "value3"}}}
I am trying to write something as-like the following in order to accomplish the above:
import json
json_data = open(json_file)
json_decoded = json.load(json_data)
# What I have to make here?!
json_data.close()
Answers:
Your json_decoded
object is a Python dictionary; you can simply add your key to that, then re-encode and rewrite the file:
import json
with open(json_file) as json_file:
json_decoded = json.load(json_file)
json_decoded['ADDED_KEY'] = 'ADDED_VALUE'
with open(json_file, 'w') as json_file:
json.dump(json_decoded, json_file)
I used the open file objects as context managers here (with the with
statement) so Python automatically closes the file when done.
You can do
json_decoded['ADDED_KEY'] = 'ADDED_VALUE'
OR
json_decoded.update({"ADDED_KEY":"ADDED_VALUE"})
which works nicely if you want to add more than one key/value pair.
Of course, you may want to check for the existence of ADDED_KEY first – depends on your needs.
AND I assume you want might want to save that data back to the file
json.dump(json_decoded, open(json_file,'w'))
Json returned from json.loads() behave just like native python lists/dictionaries:
import json
with open("your_json_file.txt", 'r') as f:
data = json.loads(f.read()) #data becomes a dictionary
#do things with data here
data['ADDED_KEY'] = 'ADDED_VALUE'
#and then just write the data back on the file
with open("your_json_file.txt", 'w') as f:
f.write(json.dumps(data, sort_keys=True, indent=4, separators=(',', ': ')))
#I added some options for pretty printing, play around with them!
For more info check out the official doc
I am new to Python and I am playing with JSON data. I would like to retrieve the JSON data from a file and add to that data a JSON key-value “on the fly”.
That is, my json_file
contains JSON data as-like the following:
{"key1": {"key1A": ["value1", "value2"], "key1B": {"key1B1": "value3"}}}
I would like to add the "ADDED_KEY": "ADDED_VALUE"
key-value part to the above data so to use the following JSON in my script:
{"ADDED_KEY": "ADDED_VALUE", "key1": {"key1A": ["value1", "value2"], "key1B": {"key1B1": "value3"}}}
I am trying to write something as-like the following in order to accomplish the above:
import json
json_data = open(json_file)
json_decoded = json.load(json_data)
# What I have to make here?!
json_data.close()
Your json_decoded
object is a Python dictionary; you can simply add your key to that, then re-encode and rewrite the file:
import json
with open(json_file) as json_file:
json_decoded = json.load(json_file)
json_decoded['ADDED_KEY'] = 'ADDED_VALUE'
with open(json_file, 'w') as json_file:
json.dump(json_decoded, json_file)
I used the open file objects as context managers here (with the with
statement) so Python automatically closes the file when done.
You can do
json_decoded['ADDED_KEY'] = 'ADDED_VALUE'
OR
json_decoded.update({"ADDED_KEY":"ADDED_VALUE"})
which works nicely if you want to add more than one key/value pair.
Of course, you may want to check for the existence of ADDED_KEY first – depends on your needs.
AND I assume you want might want to save that data back to the file
json.dump(json_decoded, open(json_file,'w'))
Json returned from json.loads() behave just like native python lists/dictionaries:
import json
with open("your_json_file.txt", 'r') as f:
data = json.loads(f.read()) #data becomes a dictionary
#do things with data here
data['ADDED_KEY'] = 'ADDED_VALUE'
#and then just write the data back on the file
with open("your_json_file.txt", 'w') as f:
f.write(json.dumps(data, sort_keys=True, indent=4, separators=(',', ': ')))
#I added some options for pretty printing, play around with them!
For more info check out the official doc