WTForms (https://github.com/wtforms/wtforms) is a standalone robust form handling library that allows you to generate HTML forms from form-like classes, implement fields and form validation, and include cross-source forgery protection (a nasty vulnerability that crackers may try to exploit in your Web applications). We certainly don't want that!

First, to install WTForms library, use the following:

pip install wtforms

Now let's write some forms. A WTForms form is a class that extends the Form class. As plain as that! Let's create a login form that could be used with our previous login example:

from wtforms import Form, StringField, PasswordField
class LoginForm(Form):
    username = StringField(u'Username:')
    passwd = PasswordField(u'Password:')

In the preceding code, we have a form with two fields, username and passwd, with no validation. It is just enough to build a form in a template, like this:

<form method='post'>
{% for field in form %}
    {{ field.label }}
 ...