Wsrtjtyk

I'm currently trying to design a filter that with it I can block certain URLs and also
block based on keywords that may be at the data that came back from the http response.

Just for clarification I'm working on a Windows 10 x64 machine for this project.

In order to be able to do such thing, I quickly understood that I would need a web proxy.
I checked out about 6 proxies written in python that I found on github.

These are the project I tried to use (some are Python3 some 2):

https://github.com/abhinavsingh/proxy.py/blob/develop/proxy.py

https://github.com/inaz2/proxy2/blob/master/proxy2.py

https://github.com/inaz2/SimpleHTTPProxy - this one is the earlier version of the top one 

https://github.com/FeeiCN/WebProxy

Abhinavsingh's Proxy (first in the list):

what I want to happen

I want the proxy to be able to block sites based on the requests and the content came back, I also need the filter to be in a separated file and to be generic
so I can apply it on every site and every request/response.

I'd like understand where is the correct place to put a filter on this proxy
and how to do redirect or just send a block page back when the client tries to access
sites that has specific urls, or when the response is a page that contains some keywords.

what I tried

I enabled the proxy on google chrome's 'Open proxy settings'
and executed the script. It looked pretty promising, and I noticed that I can insert a filterer's function call in line 383 at the _process_request function so that I can return
to it maybe another host to redirect to or just block. It worked partially for me.

The problems

First of all, I couldn't fully redirect/block the sites. Sometimes it worked, Sometimes it
didn't.
Another problem I ran into was that I realized that I can't access the content of site that returned, if it is https.

Also, filter the response was unfortunately not clear for me.

I noticed also that proxy2 (the second in the list) can solve that problem I had
of filtering https page's content, but I couldn't find out how to make this feature work (and also I think it requires linux utilities anyhow).

The process I described above was pretty much the one that I tried to work on every proxy in the list. At some proxies, like proxy2.py I couldn't understand at all what I needed to do.

If anybody managed to make a filter on top of this proxy or any other from this list and can help me understand how to do it, I'll be grateful if you'll comment down below.

Thank you.