Expose a directory on a local webserver with Python 3

Sometimes I want to view some html files from my file system in the
browser. With Python 2, you could use the SimpleHTTP-module to start a
web server with the current directory as document root like so:

    $ ls .
    foo.html
    $ python -m SimpleHTTPServer
    Serving HTTP on 0.0.0.0 port 8000 ...

On my new Linux installation Manjaro linux the Python defaults to Python
3. Today I learned how to start a web server with Python 3:

    $ ls .
    foo.html
    $ python -m http.server 8080
    Serving HTTP on 0.0.0.0 port 8080 (http://0.0.0.0:8080/) ...

The port number is optional. Open http://localhost:8080/foo.html in your
web browser to view foo.html.