Efficient way to check whether a page changed (while storing as little info as possible)?
You can keep track of the date of the last version you got and use the If-Modified-Since header in your request. However, some resources ignore that header. (In general it's difficult to handle it for dynamically-generated content.) In that case you'll have to fall back to less efficient method.
I have some webpages where I'm collecting data over time.  I don't care about the content itself, just whether the page has changed.
Currently, I use Python's requests.get to fetch a page, hash the page (md5), and store that hash value to compare in the future.
Is there a computationally cheaper or smaller-storage strategy for this?  Things work now; I just wanted to check if there's a better/cheaper way. :)