Insert nested json in Mongodb

mongodb_nested

from pymongo import MongoClient , DESCENDING , ASCENDING
mongo_uri = "mongodb://localhost:27017/"
client = MongoClient(mongo_uri)
db = client['medium_gist']

def create_collection(customer_detail):
    post = {"name": customer_detail["name"],
            "Address": customer_detail["address"],
            "items": {}
            }
    db.customer_info.insert_one(post)

def buy_item(customer_name,item_name, item_json):
    db.customer_info.update_one({"name": customer_name},
                            {"$set": {"items."+ item_name: item_json}})


# add customers 

create_collection(customer_detail = {"name": "CustomerA", "address":"AddressA"})
create_collection(customer_detail = {"name": "CustomerB", "address":"AddressB"})


transaction_detail = [{"name": "CustomerA",
                       "item": "candy",
                       "detail": {"Sixlets": 8, "Hersheys": 4}},
                      
                      {"name": "CustomerA",
                       "item": "cookie",
                       "detail": {"Oreo": 2, "Dough not": 10}},
                      
                      {"name": "CustomerB",
                       "item": "fruits",
                       "detail": {"melon":6, "kiwi": 23}
                      }]

# insert transactions
for each_transaction in transaction_detail:
    buy_item(customer_name=each_transaction['name'],
             item_name=each_transaction['item'],
             item_json=each_transaction['detail'])
             
#fetch data
def search_item(item_category, item_name=None):
    if item_name:
        return list(db.customer_info.find({"items." 
                                           + item_category + "." 
                                           + item_name:{"$exists": True}}))
    else:
        return list(db.customer_info.find({"items."
                                           + item_category:{"$exists": True}}))

search_item(item_category="fruits", item_name="melon")
search_item(item_category="cookie")