How To Filter Json Data Using Python?

How to convert JSON data from input.json to output.json using Python? In general, what data structures are used for filtering JSON data? File: input.json [ { 'id':1, 'a':22

Solution 1:

The idea is to:

• use json.load() to load the JSON content from file to a Python list
• regroup the data by the id, using collections.defaultdict and .update() method
• use json.dump() to dump the result into the JSON file

Implementation:

import json
from collections import defaultdict

# read JSON datawithopen("input.json") as input_file:
    old_data = json.load(input_file)

# regroup data
d = defaultdict(dict)
for item in old_data:
    d[item["id"]].update(item)

# write JSON datawithopen("output.json", "w") as output_file:
    json.dump(list(d.values()), output_file, indent=4)

Now the output.json would contain:

[{"d":66,"e":44,"a":22,"b":11,"c":77,"id":1,"f":55},{"b":11,"id":3,"d":44,"c":88,"a":22}]

Solution 2:

from collections import defaultdict

input_list=[{"id":1, ...}, {...}]

result_dict=defaultdict(dict)
for d in input_list:
    result_dict[d['id']].update(d)

output_list=result_dict.values()

result_dict is a default dictionary which uses a dict for every access without a available key. So we iterate through the input_list and update our result_dict with key equals id with the new values from the corresponding dictionary.

The output list is a transformation of the result_dict and uses only its values.

Use the json module to work directly with the json data.