ImportError: No module named 'toga.style'

[jedie]

setup.py django -s build the "django app" here, but the dev server starts raise into ImportError: No module named 'toga.style'

...
 * Starting Django server on localhost:8042
 * Opening browser...
Performing system checks...

Traceback (most recent call last):
  File "./manage.py", line 22, in <module>
    execute_from_command_line(sys.argv)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
    utility.execute()
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/__init__.py", line 359, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/base.py", line 294, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/commands/runserver.py", line 58, in execute
    super(Command, self).execute(*args, **options)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/base.py", line 345, in execute
    output = self.handle(*args, **options)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/commands/runserver.py", line 97, in handle
    self.run(**options)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/commands/runserver.py", line 108, in run
    self.inner_run(None, **options)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/commands/runserver.py", line 121, in inner_run
    self.check(display_num_errors=True)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/base.py", line 374, in check
    include_deployment_checks=include_deployment_checks,
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/base.py", line 361, in _run_checks
    return checks.run_checks(**kwargs)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/checks/registry.py", line 81, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/checks/urls.py", line 14, in check_url_config
    return check_resolver(resolver)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/checks/urls.py", line 24, in check_resolver
    for pattern in resolver.url_patterns:
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/urls/resolvers.py", line 313, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/urls/resolvers.py", line 306, in urlconf_module
    return import_module(self.urlconf_name)
  File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  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 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "/home/jens/repos/RunCalculator-Env/django/briefcase/urls.py", line 27, in <module>
    url(r'', TogaApp('run_calculator').urls)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/toga_django/django/__init__.py", line 16, in TogaApp
    module = importlib.import_module(module_name + ".app")
  File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  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 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "/home/jens/repos/RunCalculator-Env/src/run-calculator/run_calculator/app.py", line 13, in <module>
    from toga.style import Pack
ImportError: No module named 'toga.style'

Maybe it's related to: beeware/toga#315 (comment) ?

[jedie]

Hm. Think the problem is, that setup.py django -s will install older packages...

I start with:

pip freeze
...
-e git+https://github.com/pybee/briefcase.git@6ab9914cececeb71e5b1f034687f5943e154c071#egg=briefcase
...
-e [email protected]:jedie/RunCalculator.git@673bc84795c65952ba72a8daef376fc16644e1fe#egg=run_calculator
...
-e git+https://github.com/pybee/toga.git@02a47d27d32d16b54800b658d9afd2b316924fd1#egg=toga_core&subdirectory=src/core
-e git+https://github.com/pybee/toga.git@02a47d27d32d16b54800b658d9afd2b316924fd1#egg=toga_django&subdirectory=src/django
-e git+https://github.com/pybee/toga.git@02a47d27d32d16b54800b658d9afd2b316924fd1#egg=toga_dummy&subdirectory=src/dummy
-e git+https://github.com/pybee/toga.git@02a47d27d32d16b54800b658d9afd2b316924fd1#egg=toga_gtk&subdirectory=src/gtk
...

After running setup.py django -s i get this:

$ pip freeze
...
-e git+https://github.com/pybee/briefcase.git@6ab9914cececeb71e5b1f034687f5943e154c071#egg=briefcase
...
-e [email protected]:jedie/RunCalculator.git@673bc84795c65952ba72a8daef376fc16644e1fe#egg=run_calculator
...
toga-core==0.2.15
toga-django==0.2.15
-e git+https://github.com/pybee/toga.git@02a47d27d32d16b54800b658d9afd2b316924fd1#egg=toga_dummy&subdirectory=src/dummy
-e git+https://github.com/pybee/toga.git@02a47d27d32d16b54800b658d9afd2b316924fd1#egg=toga_gtk&subdirectory=src/gtk
...

I have removed version numbers from my setup.py, see: 

https://github.com/jedie/RunCalculator/blob/pybee/setup.py

EDIT: I "revert" the venv changes and reinstall toga from sources and try to start the django server, i get ImportError: No module named 'toga.django'

see:

$ ./django/manage.py runserver
Unhandled exception in thread started by <function check_errors.<locals>.wrapper at 0x7f045a9739d8>
Traceback (most recent call last):
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/core/management/commands/runserver.py", line 113, in inner_run
    autoreload.raise_last_exception()
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/utils/autoreload.py", line 249, in raise_last_exception
    six.reraise(*_exception)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/__init__.py", line 27, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/apps/registry.py", line 85, in populate
    app_config = AppConfig.create(entry)
  File "/home/jens/repos/RunCalculator-Env/lib/python3.5/site-packages/django/apps/config.py", line 116, in create
    mod = import_module(mod_path)
  File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 956, in _find_and_load_unlocked
ImportError: No module named 'toga.django'

[freakboy3742]

The issue isn't with the Django template; the issue is with the environment in which you're running the code (you've got Toga 0.2.15, not 0.3.0)