Change input in Python GH to text / string?

Hi I want to use Input in Python Macro as path in my Python Macro.
When I just type:
fileName = “D:___REFERENCJE_belki\single_span_girder.cdb” everything is ok and my macro is going to right file.

but when I use as input x “D:___REFERENCJE_belki\single_span_girder.cdb” and write fileName = x - Macro is not working properly.

Maybe I need to change somehow input to string?

Anyone can help?

print ( str(x) )

Input should be


without quote marks.