NULL result without error in PyObject_Call

The program can run smoothly with python command,but raise an error mentioned above when debugging in the pudb. I don't know how to deal with it and,solutions in the google search are not clear.

Start by reproducing the reported error while debugging in pudb, then compare the same program when run with the Python command. The issue does not name a file or test; done means identifying why PyObject_Call produces a NULL result without an error in pudb and verifying a fix or a clear report of the cause.

Written by the indexing model from the issue text.