ensure we follow PEP-235 on case-insensitive filesystems

[merriam]

Running PyTest with files including ZODB gives an odd problem: ZODB can be imported, but its component FileSystem cannot.

import ZODB   # That works fine.
import ZODB.FileStorage
ImportError: No module named FileStorage

On the other hand, running the same code from the Python interpreter runs fine.

This is version PyTest version 3.2.2, Python 2.7.13, and ZODB 5.2.4
There exists ZODB-5.2.4-py2.7.egg/ZODB/FileStorage/init.py, a ZODB.pth pointing to the egg, and no other modules have issues; just any submodule of ZODB. No odd permission errors. After an hour of experiments and exercising Google-Fu, I got nothing.

Any workaround would be appreciated.

[nicoddemus]

Hi, can you post a reproducible example?

[RonnyPfannschmidt]

does the error also happen when you install zodb as normal isntall instead of an egg
just to see if we mistreat eggs

[merriam]

Hi. Sorry, I got slammed and didn't make a trimmed down example. This might help:

1. The error I saw was from importing ZODB and ZODB.FileStorage in the 2.7 site-packages packages directory, from another package in the 2.7 site-packages directory.

2. Changing the import error did not help; any subpackage of ZODB causes issues, while ZODB does not.

[RonnyPfannschmidt]

again - does it work if ZODB is installed as a normal python package instead of a egg-package

[merriam]

No.

[RonnyPfannschmidt]

i see, thanks, i will try to experiment soon

[merriam]

Well, I dropped this because it 'went away'. Now its back. This I know so far:

• This shows up sometimes with PyTest, usually running a profiler. I haven't found a way around it. I don't
  know what causes it. I have some issues filed but haven't tracked it down.

  File "/Users/cmerriam/p/platform/cbmx/data/ZODB.py", line 41, in <module>
  import ZODB.FileStorage                                 # flake8: noqa
  ImportError: No module named FileStorage
  

  • Things I see:

    • Same issue from PyCharm or command line.

    • No issue running normal code from PyCharm or command line.

    • Once it starts to be an issue, it continues. Still don't know why.

    • Once it goes away it stays away.

    • My edit configuration has a warning "No Py.Test runner found for current configuration", though
      /opt/zzz/bin/py.test is in path

    • Seems to have occurred after a reboot.

    • No reason, at all, to suspect FileStorage.

    • This is in my ...../site-packages directory:

      $ ls -l ZODB*
      -rw-rw-r--  1 cmerriam  zzz  23 Oct  6 18:08 ZODB.pth
      
      ZODB-5.2.4-py2.7.egg:
      total 0
      drwxr-xr-x   9 cmerriam  zzz   306 Oct  6 18:08 EGG-INFO/
      drwxr-xr-x  74 cmerriam  zzz  2516 Oct  9 15:58 ZODB/
      
      
      $ cd ZODB-5.2.4-py2.7.egg
      $ tree
         |-EGG-INFO
         |-ZODB
         |---FileStorage
         |---__pycache__
         |---scripts
         |-----manual_tests
         |-----tests
         |---tests
      

.

• Things that haven't worked:
  • Uninstall and reinstall PyTest
  • Restart pycharm checking environment
  • Right-click in project "clean compiled python files"
  • Running regular python test first.
  • Running pytest from command line in different directories
  • Reboot again
  • Pip Install pytest-runner
  • Install new zzz version
  • Run 'python setup.py install'
  • Moving ZODB-5.2.4-py2.7.egg/EGG-INFO/ to ZODB-5.2.4-py2.7.egg-info

[merriam]

Updated more on the StackOverflow. There was a module hiding in the hierarchy named zodb.py and I'm using OS/X (case preserving, not case sensitive).

[RonnyPfannschmidt]

@merriam oh my goodness, those little traps are so devious, we could have searched for months and months without ever seeing the light

glad you discovered it in the end

[merriam]

As an FYI, there exists PEP 235 to address case sensitivity, sort of.

Would you still think of this as a problem in that Python and Py.Test created different behaviors? The offending lines were, inside of my data/zodb.py:

import ZODB  # flake8: noqa
import ZODB.FileStorage  # flake8: noqa

and in another file in the same data/ directory:

import ZODB # wanting the package ZODB in site-packages.

[RonnyPfannschmidt]

thanks for the note, i was not aware of that one,

i think now we actually have a pytest bug