求助 forms.Form 怎么定义样式

view.py：
class UserForm(forms.Form):
username = forms.CharField(label='用户名',max_length=100)
password = forms.CharField(label='密__码',widget=forms.PasswordInput())
html页面：
<div class="form-group has-feedback">
<input type="email" class="form-control" placeholder="Email">
<span class="glyphicon glyphicon-envelope form-control-feedback"></span>
</div>
<div class="form-group has-feedback">
<input type="password" class="form-control" placeholder="Password">
<span class="glyphicon glyphicon-lock form-control-feedback"></span>
</div>
实现登陆功能的时候，两个input是分别在两个div中的。