Before we implement our FTP upload functionality, it's helpful to have a test FTP service, just as we did with our test HTTP service. You can, of course, download any of a number of free FTP servers such as FileZilla, PureFTPD, ProFTPD, or others.
Rather than going to the trouble of installing, configuring, and later removing an FTP service on your system just for testing one function of an application, we can instead build a rudimentary server in Python. The third-party pyftpdlib package offers us an easy way to implement a quick-and-dirty FTP server adequate for test needs.
Install pyftpdlib using pip:
pip install --user pyftpdlib
Just like our simple HTTP server, the FTP service consists of a server object and ...
