Requirements:

pip install firebase-admin

Goto Project Settings -> Service Accounts -> Click Generate new private key and save the file as credentials.json

Write to firebase RTDB:

import firebase_admin, json
from firebase_admin import credentials, db

cred = credentials.Certificate("credentials.json")
firebase_app = firebase_admin.initialize_app(cred, {
    'databaseURL': 'https://<projectid>-default-rtdb.firebaseio.com'
})
with open("data.json") as json_file:
    data = json.load(json_file)
    ref = db.reference("sample_key")
    ref.set(data)
firebase_admin.delete_app(firebase_app)

Read from firebase RTDB:

import firebase_admin
from firebase_admin import credentials, db

cred = credentials.Certificate("credentials.json")
firebase_app = firebase_admin.initialize_app(cred, {
    'databaseURL': 'https://<projectid>-default-rtdb.firebaseio.com'
})
ref = db.reference("sample_key")
data = ref.get()
firebase_admin.delete_app(firebase_app)

RTDB security rules:

{
  "rules": {
    ".read": false,
    ".write": false
  }
}