So I don't know if this accomplishes what you are looking for or not, and my Python is still fairly minimal, so if there's a reason why this won't accomplish your need, please let me know (you'll help me learn)!
Could you have a Text Input in your workflow, with the following configuration:
Then you could connect this to the Python tool, and rename the connection as Question.SelectFile (for consistency)
Finally, you could try the following Python code:
from ayx import Alteryx
df = Alteryx.read("Question.SelectFile")
SelectFile = df.iloc['Question.SelectFile']
I believe that the SelectFile parameter referenced above should be identical to what you are looking for.