python :表单验证--对每一个输入框进行验证

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <meta charset="UTF-8"/>
    <title>Title</title>
    <style>
        .error{
            color: red;
        }
    </style>
</head>
<body>
<form id="ff" method="post">
    <div><input type="text"/></div>
    <div><input type="password"/></div>
    <div><input type="text"/></div>
    <div><input type="text"/></div>
    <div><input type="text"/></div>
    <div><input type="submit" value="提交"/></div>
</form>
<script src="jquery-1.12.4.js"></script>
<script>
    $(':submit').click(function () {
        $('.error').remove()
        var flag = true;
         $('#ff').find('input[type="text"],input[type="password"]').each(function () {

            var tag = $(this).val();
            if (tag.length <= 0) {
                flag = false;
                var  v= document.createElement('span');
                v.innerHTML = '必填';
                v.className='error';
                $(this).after(v)
                 return false
//                只提示第一个 return false
            }
        })
        return flag;

    })
</script>
</body>
</html>
提交表单验证