browser = mechanize.Browser()
parameters = {'parameter1': 'your content', 'parameter2':
    'a constant value', 'parameter3':
    'unique characters you might need to extract from the page'}
data = urllib.parse.urlencode(parameters)
browser.open(post_url, data)
browser.open(post_url + '%s' % data)
Submit without the use of a submit button, Mechanize