(I apologize if I'm doing something wrong)

When using a file named run.py in idle, any errors raised from the module makes IDLE show a traceback like this:

Traceback (most recent call last):
** IDLE Internal Exception: 
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/idlelib/run.py", line 351, in runcode
    exec(code, self.locals)
  File "/Users/Tadhg/Documents/run.py", line 1, in <module>
    raise ValueError
ValueError

I looked into idlelib.run and think the culprit is the way print_exception tries to exclude internal files, specifically line 180 in vs 2.7 and line 206 in vs3.5

            exclude = ("run.py", "rpc.py", "threading.py", "queue.py",
                       "RemoteDebugger.py", "bdb.py")

this excludes paths with these names anywhere in the path (later in cleanup_traceback) instead of getting the absolute paths of these modules.

other then bdb.py all of the excluded modules are imported into idlelib.run so that line could be replaced with:

import bdb
exclude = (__file__, rpc.__file__, threading.__file__, 
           queue.__file__, RemoteDebugger.__file__, bdb.__file__)

although it is really only necessary for run, rpc and RemoteDebugger since they are imported through `idlelib.__` so it could also use a notation like this:


exclude = ("idlelib/run.py", "idlelib/rpc.py", "threading.py", "queue.py",
           "idlelib/RemoteDebugger.py", "bdb.py")

although this would need to make use of os.path.join or equivalent to be cross compatible.

The goal is to match the traceback that Python itself produces with the same code, but it is perhaps an impossible process. The current list goes back to 2003 without tracker issue numbers, so I don't know the reason for each.  I worry a bit about the suppression of lines from threading and queue.

I wondered why the idlelib.run lines were here until I read this (3.5.2, run.py, line 233-236.

    if len(tb) == 0:
        # exception was in IDLE internals, don't prune!
        tb[:] = orig_tb[:]
        print("** IDLE Internal Exception: ", file=sys.stderr)

So both lines were deleted and then restored.

Prepending idlelib as appropriate, seems like a good idea.

    exclude = ['bdb.py', 'queue.py', 'threading.py']
    for name in ('RemoteDebugger.py', 'rpc.py', 'run.py'):
        exclude.append(os.path.join('idlelib', name))

Duplicate issue24252, although the consequences are slightly different.