Flask 如何创建宏来清除WTForm错误检查？

是否有更好的方法在我的表单字段中设置“has error”类？我用的是烧瓶和表格。下面的代码可以工作，但非常重复。我试图设置一个动态变量，例如

{%set field+'error'='有错误“%}

，但发现您无法在jinja中设置动态变量

<form action="{{ url_for_security('login') }}" method="POST" name="login_user_form">
    {% if login_user_form.email.errors %}
        {% set email_error = 'has-error' %}
    {% endif %}
    {% if login_user_form.password.errors %}
        {% set password_error = 'has-error' %}
    {% endif %}

    <div class="form-group {{ email_error }}">
        {{ login_user_form.email(class='form-control input-lg', placeholder='Email', required='true') }}
        {% if login_user_form.email.errors %}
            {% for error in login_user_form.email.errors %}
                <span class="help-block">{{ error }}</span>
            {% endfor %}
        {% endif %}
    </div> <!-- / Email -->

    <div class="form-group signin-password {{ password_error }}">
        {{ login_user_form.password(class='form-control input-lg', placeholder='Password', required='true') }}
        {% if login_user_form.password.errors %}
            {% for error in login_user_form.password.errors %}
                <span class="help-block">{{ error }}</span>
            {% endfor %}
        {% endif %}
    </div> <!-- / Password -->

    <div class="form-actions">
        <input type="submit" value="Log In" class="btn btn-primary btn-block btn-lg">
    </div> <!-- / .form-actions -->
</form>

{%if login\u user\u form.email.errors%}
{%set email_error='有错误“%”
{%endif%}
{%if login\u user\u form.password.errors%}
{%set password_error='有错误“%}
{%endif%}
{{login\u user\u form.email（class='form-control input lg'，placeholder='email'，required='true'）}
{%if login\u user\u form.email.errors%}
{%for登录时出错\u user\u form.email.errors%}
{{error}}
{%endfor%}
{%endif%}
{{login\u user\u form.password（class='form-control input lg'，placeholder='password'，required='true'）}
{%if login\u user\u form.password.errors%}
{%for登录时出错\u user\u form.password.errors%}
{{error}}
{%endfor%}
{%endif%}