jinja2.exceptions.TemplateSyntaxError: expected token 'end of statement block', got 'post'

I am creating a form using python/flask, but getting the error that I posted in the title. I am not able to figure out where the problem is. Can you please help!

{% extends "base.html %}
{% block content %}
<h1>Sign In</h1>
<form action="" method="post">
    {{ form.hidden_tag() }}
    <p>
        {{ form.username.label }}<br>
        {{ form.username(size=32) }}
    </p>
    <p>
        {{ form.password.label }}<br>
        {{ form.password(size=32) }}
    </p>
    <p>{{ form.remember_me() }} {{ form.remember_me.label }}</p>
    <p>{{ form.submit() }}</p>
</form>
{% endblock %}