Sorting and Merging text-files [SOLVED]

[AlphaInc]

Thanks also for your help. I can see that the Script process all my files but it does not create an output-file

Edit: My Bad, just looked after the wrong name. I found it. Thank you.

Sorry once again but I get an error:

Traceback (most recent call last):
  File "FileProcessing_11.py", line 30, in <module>
    sorted_outputs = sorted(outputs.glob(search), key=sort_by_int)
  File "FileProcessing_11.py", line 13, in sort_by_int
    return int(path.stem.split("_", maxsplit=1)[1])
IndexError: list index out of range

Could it be because the files got spaces in it?