Make all file references relative in a Nuke script when they start with the project directory (case-sensitive)

make_file_paths_relative.py

def remove_prefix(text, prefix):
    if text.startswith(prefix):
        return text[len(prefix):]
    return text

undo = nuke.Undo()
undo.begin("make file paths relative")

project_dir = nuke.Root()['project_directory'].value()
if not project_dir.endswith('/'):
    project_dir += '/'

for n in nuke.allNodes():
    k = n.knob('file')
    if k != None:
        current_path = k.value()
        relative_path = remove_prefix(current_path, project_dir)
        k.setValue(relative_path)

undo.end()