Error Converting circular structure to JSON, while sending json from Flask to Node.js

from receipt import receiptDict
from flask import Flask, jsonify # <--- import this jsonify here
import json
app = Flask(__name__)


@app.route('/')
def index():
    return jsonify(receiptDict)

if  __name__ == '__main__':
    app.run(debug=True)

 return res.send(receipt.data)