TypeError: expected str, bytes or os.PathLike object, not NoneType

[duanyuj]

Sir, I have encountered a question. How can I resolve it? Thanks.

Traceback (most recent call last):
File "QT-GILD.py", line 161, in
main()
File "QT-GILD.py", line 149, in main
working_folder_creation(gt_path,temp_dir,arguments.mode)
File "QT-GILD.py", line 56, in working_folder_creation
shutil.copy2(gt_path,final_gt)
File "/home/yujie/anaconda3/envs/py37/lib/python3.7/shutil.py", line 265, in copy2
dst = os.path.join(dst, os.path.basename(src))
File "/home/yujie/anaconda3/envs/py37/lib/python3.7/posixpath.py", line 146, in basename
p = os.fspath(p)
TypeError: expected str, bytes or os.PathLike object, not NoneType