Why can't Jupyter notebook open Kernel? - python-3.x

Question

I recently installed Jupyter on a new computer and after trying with and without virtualenv, I receive the following errors related to the threading module. This error prevents the notebook from either (1) opening or (2) starting the kernel.
Error upon opening python -m notebook. Notebook doesn't open successfully.
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/runpy.py", line 183, in _run_module_as_main
mod_name, mod_spec, code = _get_module_details(mod_name, _Error)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/runpy.py", line 142, in _get_module_details
return _get_module_details(pkg_main_name, error)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/runpy.py", line 109, in _get_module_details
__import__(pkg_name)
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/notebook/__init__.py", line 25, in <module>
from .nbextensions import install_nbextension
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/notebook/nbextensions.py", line 31, in <module>
from .config_manager import BaseJSONConfigManager
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/notebook/config_manager.py", line 15, in <module>
from traitlets.config import LoggingConfigurable
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/traitlets/config/__init__.py", line 6, in <module>
from .application import *
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/traitlets/config/application.py", line 11, in <module>
import logging
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/logging/__init__.py", line 210, in <module>
_lock = threading.RLock()
AttributeError: module 'threading' has no attribute 'RLock'
Exception ignored in: <module 'threading' from '/Users/me/Downloads/threading.py'>
AttributeError: module 'threading' has no attribute '_shutdown'
Error after switching directory, opening notebook successfully, and attempting to connect to kernel
[I 09:32:05.828 NotebookApp] KernelRestarter: restarting kernel (3/5), new random ports
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/runpy.py", line 193, in _run_module_as_main
"__main__", mod_spec)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/runpy.py", line 85, in _run_code
exec(code, run_globals)
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/ipykernel_launcher.py", line 15, in <module>
from ipykernel import kernelapp as app
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/ipykernel/__init__.py", line 2, in <module>
from .connect import *
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/ipykernel/connect.py", line 13, in <module>
from IPython.core.profiledir import ProfileDir
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/IPython/__init__.py", line 54, in <module>
from .core.application import Application
File "/Users/me/Documents/Code/Python/Environments/Jupyter/lib/python3.7/site-packages/IPython/core/application.py", line 18, in <module>
import logging
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/logging/__init__.py", line 210, in <module>
_lock = threading.RLock()
AttributeError: module 'threading' has no attribute 'RLock'
Exception ignored in: <module 'threading' from '/Users/me/Downloads/threading.py'>
AttributeError: module 'threading' has no attribute '_shutdown'
Seeing as threading is a built-in module, I cannot update it. Again, this result is identical using the normal site-packages installation and a clean virtualenv installation.

Answer 1

I found that this error was caused because a file named threading.py (not related to the built-in module) existed in a subdirectory of my home directory. If I launched the notebook from any directory where the file was anywhere in the directory tree below my current directory, I would receive this error.
The solution is to launch the notebook in a directory where a naming conflict with the built-in threading does not exist.
The odd thing is that if I import threading in a Python shell in the same directories where the failures occurred and run dir(threading), it picks up the correct package. Why does Jupyter treat this differently?