How to convert nested json with same data to CSV python

Question

I have json data with nested arrays which contains same key name. My Json format is like(may vary key value pair names):

{
  "name": "bharat",
  "age": 27, 
  "vehicles": [
      {
          "car": "tata",
          "bike": "duke",
          "plane": "n",            
      },
      {
          "car": "odi",
          "bike": "duke",
          "plane": "n",       
      }]
 }

I have tried Convert nested JSON to CSV file in Python but got multiple columns with same keys in vehicles.

My code is

import json
import csv
from elasticsearch import Elasticsearch
import elasticsearch.helpers

with open("query.json") as f:
  query=json.load(f)

es = Elasticsearch(['http://xx.xx.xx.xx:xxxx'],verify_certs=False)

results_gen = elasticsearch.helpers.scan(
    es,
    query=query,
    index="demo",
)

def get_leaves(item, key=None):
    if isinstance(item, dict):
        leaves = []

        for i in item.keys():
            leaves.extend(get_leaves(item[i], i))
        return leaves
    elif isinstance(item, list):
        leaves = []
        for i in item:
            leaves.extend(get_leaves(i, key))
        return leaves
    else:
        return [(key, item)]

with  open('Data.csv', 'w', newline='') as f_output:
    csv_output = csv.writer(f_output)
    write_header = True

    for entry in results_gen:
        e=entry['_source']

        leaf_entries = sorted(get_leaves(e))
    print(leaf_entries)
        if write_header:
            csv_output.writerow([k for k, v in leaf_entries])
            write_header = False
        csv_output.writerow([v for k, v in leaf_entries])

I am getting output like

name    age    car    car  bike   bike plane plane
bharat  27     tata   odi  duke    duke  n     n

I expect output to be like

name    age    car    bike    plane
bharat  27     tata   duke    n     
bharat  27     odi    duke    n

Answer 1

Something like this (Assuming you are interested in vehicles data only)

data = {"name": "bharat", "age": 27, "vehicles": [{"car": "tata", "bike": "duke", "plane": "n",
                                                   }, {"car": "odi", "bike": "duke", "plane": "n",
                                                       }]}
with open('out.csv', 'w') as out:
    for v in data['vehicles']:
        line = ','.join(v.values())
        out.write(line + '\n')

Answer 2

You Can use Pandas Normalize class to normalize the json into pandas dataframe and then write the dataframe to csv

Lets say you have Json dictionaries in variable 'data' like: [{json1},{json2},{json3}...]

    import json
    import pandas
    from pandas.io.json import json_normalize

    for d in data:
        normalized_data = json_normalize(d)
        normalized_data .to_csv('csv_file_name', sep='|', mode='a', index=False, na_rep='', header=False)

refer: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.io.json.json_normalize.html