code: def findall(dir=os.curdir):
      
      files = _find_all_simple(dir)
      if dir == os.curdir:
          make_rel = functools.partial(os.path.relpath, start=dir)
          files = map(make_rel, files)
      return list(files)
docs: Find all files under 'dir' and return the list of full filenames.
      Unless dir is '.', return full filenames with dir prepended.