smandape 0 Newbie Poster

I am trying to do some web scraping on this site. So far I have tried the following but the output it gives me is the source code of the site which is different than I expect. I am trying to follow this link which has done webscraping in ruby. Any help is greatly appreciated. Here is the code so far:

import mechanize
import shutil
br = mechanize.Browser()
br.open("http://www.ncbi.nlm.nih.gov/pmc/pmctopmid/")
br.form = list(br.forms())[1]
br.form.find_control(name='PAFAppLayout.AppController.Page.PMCToPmidC.MainPortlet.from_db').items[0].selected = True
br.form['PAFAppLayout.AppController.Page.PMCToPmidC.MainPortlet.Ids'] = "21707345\n23482678"
br.form.find_control(name='PAFAppLayout.AppController.Page.PMCToPmidC.MainPortlet.ToFile').items[0].selected = True
br.form.find_control(name='ConvertButton').selected = True
with open('output_converter.csv','wb') as f:
    shutil.copyfileobj(br.submit(),f)