title: Submit form using urllib
body: <p>In Python 2, while submitting forms in webpage, we can use mechanize. Also we can see the forms in the webpage using. But how to do that using urllib in Python 3(i.e finding the forms and submitting the values). I know how to use POST to submit the forms in urllib. But how to fnd the forms? and also how to override the readonly values using urllib?</p>