如何在Python (Flask)应用程序中捕获psycopg2.errors.UniqueViolation错误？

from flask import Flask, jsonify
import psycopg2
from psycopg2 import errors

app = Flask(__name__)

def insert_data(data):
    conn = psycopg2.connect(database="yourdb", user="youruser", password="yourpass", host="yourhost", port="yourport")
    cur = conn.cursor()
    
    try:
        cur.execute("INSERT INTO yourtable (unique_field) VALUES (%s)", (data,))
        conn.commit()
    except errors.UniqueViolation as e:
        conn.rollback()
        return jsonify({"error": "Duplicate entry for unique field: {}".format(data)}), 409
    finally:
        cur.close()
        conn.close()

@app.route('/insert', methods=['POST'])
def insert():
    data = request.json.get('data')
    if data:
        return insert_data(data)
    else:
        return jsonify({"error": "No data provided"}), 400

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