Error in atexit._run_exitfuncs:

Created originally on Bitbucket by bogdantabacaru (Bogdan Tabacaru)

Hi everyone,

I discovered an issue when testing an openpyxl 2.5.1 application with setup.py and py.test.

It occurs when using Python 2.7.14.

It does not occur on Python 3.6.3.

I haven't tried other Python versions.

PFA the minimum setup necessary to reproduce the bug.

Let me know if I should provide any other information to fix this bug.

Description

To reproduce the issue, I created a simple program which opens an XLSX file and saves it under a different name. Additionally, I created a test case using unittest.

I am executing the test as explained here:

https://pypi.python.org/pypi/pytest-runner

Trace Dump

#!bash
python setup.py pytest
running pytest
running egg_info
creating UNKNOWN.egg-info
writing requirements to UNKNOWN.egg-info/requires.txt
writing UNKNOWN.egg-info/PKG-INFO
writing top-level names to UNKNOWN.egg-info/top_level.txt
writing dependency_links to UNKNOWN.egg-info/dependency_links.txt
writing manifest file 'UNKNOWN.egg-info/SOURCES.txt'
reading manifest file 'UNKNOWN.egg-info/SOURCES.txt'
writing manifest file 'UNKNOWN.egg-info/SOURCES.txt'
running build_ext
============================================================ test session starts =============================================================
platform linux2 -- Python 2.7.14, pytest-3.2.1, py-1.4.34, pluggy-0.4.0
rootdir: /home/boggers/eclipse-workspace/openpyxl_write_only_atexit_issue, inifile:
collected 1 item                                                                                                                              

test_main.py .

========================================================== 1 passed in 0.18 seconds ==========================================================
Error in atexit._run_exitfuncs:
Traceback (most recent call last):
  File "/usr/lib/python2.7/atexit.py", line 24, in _run_exitfuncs
    func(*targs, **kargs)
  File "/usr/local/lib/python2.7/dist-packages/openpyxl/worksheet/write_only.py", line 31, in _openpyxl_shutdown
    for path in ALL_TEMP_FILES:
TypeError: 'NoneType' object is not iterable
Error in sys.exitfunc:
Traceback (most recent call last):
  File "/usr/lib/python2.7/atexit.py", line 24, in _run_exitfuncs
    func(*targs, **kargs)
  File "/usr/local/lib/python2.7/dist-packages/openpyxl/worksheet/write_only.py", line 31, in _openpyxl_shutdown
    for path in ALL_TEMP_FILES:
TypeError: 'NoneType' object is not iterable

My Two Cents

For some reason, the global list ALL_TEMP_FILES is treated as None when running the _openpyxl_shutdown() method. If I simply add and if statement that returns if the list is None (see below), this issue does not occur any more. However, I am not sure about the consequences of this dumb if statement.

#!python

@atexit.register
def _openpyxl_shutdown():
    global ALL_TEMP_FILES
    if ALL_TEMP_FILES is None:
        return
    for path in ALL_TEMP_FILES:
        if os.path.exists(path):
            os.remove(path)

On a different note, I also found this open issue. Is it possible that they are related?

https://bitbucket.org/openpyxl/openpyxl/issues/838/write_only-atexit-not-safe

Attachments: openpyxl_write_only_atexit_issue.zip