CGI scripts have much of PHPs simplicity. You can just drop in a executable file, and depending bit on server configuration, it will just run. With Python a basic hello world would look something like this:

    #!/usr/bin/python
    
    print "Content-type: text/plain"
    print ""
    print "Hello World!"

So 3 lines of "boilerplate", and then you can do anything you want. No extra packages to install or languages to learn. No frameworks necessary.

edit: just as an example of minimal hello world in WSGI:

    def application(environ, start_response):
        start_response('200 OK', [('Content-type', 'text/plain')])
        yield 'Hello World!'

also doesn't need any extra python packages or frameworks. but configuring web server to handle wsgi is bit more involved than cgi.