Don't depend on pkg_resources

[ataylor32]

Expected Behavior

I should be able to run a command like python manage.py shell without any errors.

Current Behavior

[ERROR] management_commands File "/var/www/example.com/manage.py", line 33: Management command error: manage.py shell
Traceback (most recent call last):
  File "/var/www/example.com/manage.py", line 31, in main
    execute_from_command_line(sys.argv)
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
    utility.execute()
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 416, in execute
    django.setup()
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/apps/registry.py", line 91, in populate
    app_config = AppConfig.create(entry)
                 ^^^^^^^^^^^^^^^^^^^^^^^
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/apps/config.py", line 193, in create
    import_module(entry)
  File "/usr/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 995, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/var/www/example.com/venv/lib/python3.12/site-packages/user_sessions/__init__.py", line 1, in <module>
    from pkg_resources import DistributionNotFound, get_distribution
ModuleNotFoundError: No module named 'pkg_resources'

Your Environment

• Python version: 3.12.3
• Django version: 4.2.11
• django-user-sessions version: 2.0.0

Relevant: python/cpython#95299

[WhyNotHugo]

pkg_resources is used to read the current package version.

We should probably write the version into a file at build time instead with something like:

[build-system]
requires = ["setuptools>=45", "wheel", "setuptools_scm>=6.2"]

[tool.setuptools_scm]
write_to = "user_sessions/version.py"
version_scheme = "no-guess-dev"

init.py can then use:

from . import version

__version__ = version.version

[aradfarahani]

The error you're encountering, ModuleNotFoundError: No module named 'pkg_resources', typically occurs when the setuptools package is not installed or is not properly configured in your Python environment. Here are some steps to resolve this issue:

Steps to Fix the Error

1. Install or Upgrade setuptools:
   Ensure that setuptools is installed and up-to-date. You can do this by running the following commands:

   pip install --upgrade setuptools

2. Uninstall and Reinstall setuptools:
   If the above step doesn't work, try uninstalling and then reinstalling setuptools:

   pip uninstall -y setuptools
   pip install setuptools

3. Upgrade pip, setuptools, and wheel:
   Sometimes, upgrading pip, setuptools, and wheel can resolve the issue:

   # For Unix/macOS
   python3 -m pip install --upgrade pip setuptools wheel
   
   # For Windows
   py -m pip install --upgrade pip setuptools wheel

4. Create a Virtual Environment:
   If the issue persists, try creating a new virtual environment and installing the necessary packages within it:

   # For Unix/macOS
   python3 -m venv my_env
   source my_env/bin/activate
   
   # For Windows
   py -m venv my_env
   my_env\Scripts\activate
   
   # Then install the required packages
   pip install django django-user-sessions

Example Configuration for setuptools_scm

If you need to write the version into a file at build time, you can configure setuptools_scm as follows:

1. Add setuptools_scm to your pyproject.toml:

   [build-system]
   requires = ["setuptools>=45", "wheel", "setuptools_scm>=6.2"]
   
   [tool.setuptools_scm]
   write_to = "user_sessions/version.py"
   version_scheme = "no-guess-dev"

2. Modify __init__.py:
   In your __init__.py, use the following code to import the version:

   from . import version
   
   __version__ = version.version

By following these steps, you should be able to resolve the ModuleNotFoundError: No module named 'pkg_resources' and run python manage.py shell without any errors.