flask html页面中放动态链接

{% block head %}
 {{ super() }}
 <link rel="shortcut icon" href="{{ url_for('static', filename = 'favicon.ico') }}"
 type="image/x-icon">
 <link rel="icon" href="{{ url_for('static', filename = 'favicon.ico') }}"
 type="image/x-icon">
 {% endblock %}
url_for('user', name='john', _external=True)
 url_for('index', page=2)
 url_for('static', filename='css/styles.css', _external=True)