Can't get the whole source of an html page
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Using python, I want to crawl data on a web page whose source if quite big (it is a facebook page of some user). 

Say url is the url I am trying to crawl. I run the following code:

    import urllib2
    
    usock = urllib2.urlopen(url)
    data = usock.read()
    usock.close()

data is supposed to contain the source of the page I am crawling, but for some reason, it doesn't contain all the characters. That are available when I compare directly with the source of the page. I don't know what I am doing wrong. I know that the page I am trying to crawl has not been updated recently, so it is not due to the fact that I am missing some very recent data.

Does someone have a clue?

Thanks!