stftpd 0.1.0 a Single-File TFTP Server has been released.
The released version 0.1.0 is a proof of concept. But it can already be used to experiment with the TFTP protocol.
The main goals are simplicity and portability. Only core functions of Python 2 and Python 3 have been used to implement the server.
Feel free to use stftpd as a standalone server or to write your own using the provided Python API. You can grab the source code from the stftpd repository on GitHub.