Convert Json to flat CSV

json_to_csv.py

import pandas as pd
from pandas.io import json
from pandas.io.json import json_normalize

with open('data.json') as f:
    data = json.loads(f.read())

def normalize(o):
    dict_obj = {}
    items = []
    list_items = []

    def inner(x, key):
        for k, v in x.items():
            if key == '':
                item_key = k
            else:
                item_key = '{}.{}'.format(key, k)

            if isinstance(v, dict):
                inner(v, item_key)
            else:
                if isinstance(v, list):
                    list_items.append(item_key)
                dict_obj[item_key] = v

    for item in o:
        if isinstance(item, dict):
            inner(item, '')

            if len(list_items) > 0:
                _list_l1 = []
                _list_ln = []
                list_items.sort()

                col_key = list_items.pop()
                if len(dict_obj[col_key]) > 0:
                    for _v in dict_obj[col_key]:
                        t = dict_obj.copy()
                        t[col_key] = _v
                        _list_l1.append(t)
                else:
                    t = dict_obj.copy()
                    t[col_key] = None
                    _list_l1.append(t)

                
                if len(list_items) > 0:
                    while len(list_items) > 0:
                        col_key = list_items.pop()
                        for _v in dict_obj[col_key]:
                            for _l in _list_l1:
                                t = _l.copy()
                                t[col_key] = _v
                                _list_ln.append(t)
                        _list_l1 = _list_ln.copy()
                        _list_ln.clear()

                if len(_list_l1) > 0:
                    items.extend(_list_l1)
            else:
                items.append(dict_obj)
            del item

    return items    
    
data = normalize(data)
df = json_normalize(data)

df.to_csv('data.csv', index=False)