I need to create a script that will log into an authenticated page and download a pdf. 
However, the pdf that I need to download is not at a URL, but it is generated upon clicking on a specific input button on the page. When I check the HTML source, it only gives me the url of the button graphic and some obscure name of the button input, and action=".".
In addition, both the url where the button is and the form name is obscured, for example:

url = /WebObjects/MyStore.woa/wo/5.2.0.5.7.3
input name = 0.0.5.7.1.1.11.19.1.13.13.1.1

How would I log into the page, 'click' that button, and download the pdf file within a script?
Try mechanize or twill. HttpFox or firebug can help you to build your queries. Remember you can also pickle cookies from browser and use it later with py libs. If the code is generated by javascript it could be possible to 'reverse engineer' it. If nof you can run some javascript interpret or use selenium or windmill to script a real browser.
Advanced screen-scraping using curl