The data type calculated when python connects to a database using select sum(a) from b is Decimal. But this format doesn’t fit the json format, so we can cast the data we get. Convert to an integer, and you’ll be able to fit the JSON format.

@app.route('/c1')
def get_cl_data():
    data = utils.get_conn()
    # data = json.dumps({"confirm": data[0], "suspect": data[1], "heal": data[2], "dead": data[3]})
    # print(data)
    return jsonify({"confirm": int(data[0]), "suspect": int(data[1]), "heal": int(data[2]), "dead": int(data[3])})

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