n00b help with referencing files

[DeaD_EyE]

I have a script that basically modifies a file. In a nutshell, fileA contains some text, and the script reads fileA and uses the text to modify fileB. fileA is in a different directory than fileB, and I have multiple iterations of this. So I've hardcoded the paths in the script to fileA and fileB, but basically I need the script to iterate over multiple paths that contain fileA and fileB. Hopefully this makes sense.

Maybe you post some content of fileA and of fileB and your script.
My line of thinking: paths in fileA and fileB should be relative. Then you should have a absolute base directory stores inside your script or as env variable or in a config file. Then joining them together os.path.join(base_path, path_from_text_file). This prevents you from manipulating the path with string interpolation and it is os independent. But when the files are already done and have for example 16k lines, you must handle it like ichabod801 has shown. My suggestion is always, don't use absolute paths in files, which you want to process later. If you want to move the files to a different place and all paths are absolute, you'll have to handle this in your script also or doing the trick with a symlink.