pytest not run

I launched a project. After creating the model, I’m trying to run tests. But I get an error.

ERROR collecting server/apps/main/admin.py 
server/apps/main/admin.py:12: in <module>
    admin.site.register(File, Dd)
.venv/lib/python3.7/site-packages/django/contrib/admin/sites.py:110: in register
    raise AlreadyRegistered('The model %s is already registered' % model.__name__)
E   django.contrib.admin.sites.AlreadyRegistered: The model File is already registered

ERROR collecting server/apps/main/models.py 
server/apps/main/models.py:28: in <module>
    class File(AbstractDefaultModel):
.venv/lib/python3.7/site-packages/django/db/models/base.py:118: in __new__
    "INSTALLED_APPS." % (module, name)
E   RuntimeError: Model class main.models.File doesn't declare an explicit app_label and isn't in an application in INSTALLED_APPS.

my code models.py

class AbstractDefaultModel(models.Model):
    is_active = models.BooleanField(
        verbose_name=_('is_active'),
        default=True)

    created_at = models.DateTimeField(
        verbose_name=_('created at'),
        auto_now_add=True)

    updated_at = models.DateTimeField(
        verbose_name=_('updated at'),
        auto_now=True)

    def __str__(self):
        return '{id}'.format(id=self.id)

    class Meta:
        abstract = True

class File(AbstractDefaultModel):
    code = models.PositiveIntegerField(
        verbose_name='code',
        unique=True,
        editable=True)

    profile = models.CharField(
        verbose_name='name',
        max_length=100,
        blank=True,
        null=True)

    class Meta:
        verbose_name = 'file'
        verbose_name_plural = 'files'

my code admin.py

from server.apps.main.models import File
class FileAdmin(admin.ModelAdmin):
    list_display = ['id', 'profile']

admin.site.register(File, FileAdmin)

[vaad2]

The problem with test, because pydoc builds module path from package (folder with init.py). For example: you have server/apps/main/models Pydoc scans and look into parent folder - models. If init.py exists, it add to path models. Then pydoc go up to top folder - main, which have _init.py. Now current path - main.models, but apps folder - without init. Django builds modules path differently. As result main.models (from pydoc) != server.apps.main.models (from django)

Solution: add init.py into apps dir

[sobolevn]

@vaad2 thanks! Do you want to send a PR with the fix?