无法解析其余部分：'forloop .counter'中的'.counter'

Question

< h1 > {{ question.question_text }} </ h1 >

{% if error_message %} < p >< strong > {{ error_message }} </ strong ></ p > {% endif %}

<form action = " {% url 'polls:vote' question.id %} " method = "post" >
{% csrf_token %}
{% for choice in question.choice_set.all %}
    <% input type = "radio" name = "choice" id = "choice {{ forloop .counter }} " value = " {{ choice.id }} "% >
    < label for = "choice {{ forloop .counter }} " > {{ choice.choice_text }} </ label >< br >
{% endfor %}
< input type = "submit" value = "Vote" >
</form >

我在运行命令时遇到此错误：python manage.py runserver

  

django.template.exceptions.TemplateSyntaxError：无法解析“ forloop .counter”中的其余部分：“。counter”

如何解决此错误？