Can Not execute Python .py file using RobotFramework like Javascript
The Execute Javascript extension isn't a part of RobotFramework, it's something added by the Selenium integration, it would therefore follow that you can't use Selenium to execute a .py file.
That said, RobotFramework is written in Python and can obviously be extended with a Python script.
Can you clear up what you're actually trying to achieve here though?
My concern is that if you're using a .py file in your test state to validate your code, isn't that introducing an uncertainty that means that what you're testing is not the same as the code that gets executed when you release your project?
A bit more detail would help a lot here!
Has anyone found a method for executing their .py files from the Robot Framework like you can for JS? 
RobotFramework: 

Executes the given JavaScript code.
code may contain multiple statements and the return value of last
  statement is returned by this keyword.
code may be divided into multiple cells in the test data. In that
  case, the parts are catenated together without adding spaces.
If code is an absolute path to an existing file, the JavaScript to
  execute will be read from that file. Forward slashes work as a path
  separator on all operating systems. The functionality to read the code
  from a file was added in SeleniumLibrary 2.5.
Note that, by default, the code will be executed in the context of the
  Selenium object itself, so this will refer to the Selenium object. Use
  window to refer to the window of your application, e.g.
  window.document.getElementById('foo').
Example: Execute JavaScript   window.my_js_function('arg1', 'arg2')
  Execute JavaScript    ${CURDIR}/js_to_execute.js

It's bs that I can't run my .py files this way...