AttributeError: type object 'NullTranslations' has no attribute '_instance'

[tylerjw]

Here is the output I get. I'm on Ubuntu 16.04 and am using the built in python3.5.

Traceback (most recent call last):
  File "/usr/lib/python3.5/runpy.py", line 184, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib/python3.5/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "aptsources-cleanup.zip/__main__.py", line 8, in <module>
  File "/usr/lib/python3.5/runpy.py", line 192, in run_module
    mod_name, mod_spec, code = _get_module_details(mod_name)
  File "/usr/lib/python3.5/runpy.py", line 133, in _get_module_details
    return _get_module_details(pkg_main_name, error)
  File "/usr/lib/python3.5/runpy.py", line 109, in _get_module_details
    __import__(pkg_name)
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 664, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 634, in _load_backward_compatible
  File "aptsources-cleanup.zip/aptsources_cleanup/__init__.py", line 23, in <module>
  File "aptsources-cleanup.zip/aptsources_cleanup/util/import_check.py", line 39, in import_check
  File "aptsources-cleanup.zip/aptsources_cleanup/util/functools.py", line 137, in <lambda>
    def _lt_from_gt(self, other, NotImplemented=NotImplemented):
  File "aptsources-cleanup.zip/aptsources_cleanup/util/functools.py", line 102, in __getattr__
    return not op_result and self != other
AttributeError: type object 'NullTranslations' has no attribute '_instance'

[davidfoerster]

Thanks for your report. I’m investigating the issue.

[ed-dev]

Ubuntu 16.04, python 3.5.2

Traceback (most recent call last):
 File "/usr/lib/python3.5/runpy.py", line 184, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib/python3.5/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "aptsources-cleanup.zip/__main__.py", line 8, in <module>
  File "/usr/lib/python3.5/runpy.py", line 199, in run_module
    return _run_code(code, {}, init_globals, run_name, mod_spec)
  File "/usr/lib/python3.5/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "aptsources-cleanup.zip/aptsources_cleanup/__main__.py", line 365, in <module>
  File "aptsources-cleanup.zip/aptsources_cleanup/__main__.py", line 32, in main
  File "aptsources-cleanup.zip/aptsources_cleanup/__main__.py", line 196, in parse_args
  File "aptsources-cleanup.zip/aptsources_cleanup/util/functools.py", line 137, in <lambda>
    def _lt_from_gt(self, other, NotImplemented=NotImplemented):
  File "aptsources-cleanup.zip/aptsources_cleanup/util/functools.py", line 102, in __getattr__
    return not op_result and self != other
AttributeError: type object 'NullTranslations' has no attribute '_instance'

[davidfoerster]

It took a while but I can reproduce the issue now. I had to install Python v3.5 since this never happens with v3.6. It also only happens when running the ZIP package (instead of unpackaged source code files).

I understand how it happens but not why.

[ed-dev]

Thanks. Using the source is a good work around. I downloaded the source, followed the README.md and it worked perfectly using v3.5.2

[davidfoerster]

I think this is a bug in (Ubuntu’s) Python v3.5: In the class LazyInstance, _instance is a (known) @property. Known attributes are not supposed to be accessed via the __getattr__ special method. Nonetheless, the attribute (property) access to self._instance triggers a call to self.__getattr__('_instance'). Weird. Even weirder that this only happens from within the ZIP code archive.

I worked around the issue with a regular instance method instead of a property and will push an update soon.