#23455: migrations created with python2 break with python3
----------------------------+--------------------
Reporter: brian | Owner: nobody
Type: Bug | Status: new
Component: Migrations | Version: 1.6
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
----------------------------+--------------------
As an example, my model has:
{{{
@python_2_unicode_compatible
class Institute(models.Model):
...
delegates = models.ManyToManyField(
Person, related_name='delegate_for',
blank=True, null=True, through='InstituteDelegate')
...
}}}
makemigrations running under Python2 turns this into:
{{{
migrations.AddField(
model_name='institute',
name='delegates',
field=models.ManyToManyField(related_name=b'delegate_for', null=True,
through='karaage.InstituteDelegate', to='karaage.Person', blank=True),
preserve_default=True,
),
}}}
This works fine under Python2, where `b''` == `''`.
Under Python3 however, I get:
{{{
Traceback (most recent call last):
File "./manage.py", line 7, in <module>
management.execute_from_command_line()
File "/usr/lib/python3/dist-
packages/django/core/management/__init__.py", line 385, in
execute_from_command_line
utility.execute()
File "/usr/lib/python3/dist-
packages/django/core/management/__init__.py", line 377, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/usr/lib/python3/dist-
packages/django/core/management/commands/test.py", line 50, in
run_from_argv
super(Command, self).run_from_argv(argv)
File "/usr/lib/python3/dist-packages/django/core/management/base.py",
line 288, in run_from_argv
self.execute(*args, **options.__dict__)
File "/usr/lib/python3/dist-
packages/django/core/management/commands/test.py", line 71, in execute
super(Command, self).execute(*args, **options)
File "/usr/lib/python3/dist-packages/django/core/management/base.py",
line 338, in execute
output = self.handle(*args, **options)
File "/usr/lib/python3/dist-
packages/django/core/management/commands/test.py", line 88, in handle
failures = test_runner.run_tests(test_labels)
File "/usr/lib/python3/dist-packages/django/test/runner.py", line 147,
in run_tests
old_config = self.setup_databases()
File "/usr/lib/python3/dist-packages/django/test/runner.py", line 109,
in setup_databases
return setup_databases(self.verbosity, self.interactive, **kwargs)
File "/usr/lib/python3/dist-packages/django/test/runner.py", line 299,
in setup_databases
serialize=connection.settings_dict.get("TEST_SERIALIZE", True),
File "/usr/lib/python3/dist-packages/django/db/backends/creation.py",
line 374, in create_test_db
test_flush=True,
File "/usr/lib/python3/dist-
packages/django/core/management/__init__.py", line 115, in call_command
return klass.execute(*args, **defaults)
File "/usr/lib/python3/dist-packages/django/core/management/base.py",
line 338, in execute
output = self.handle(*args, **options)
File "/usr/lib/python3/dist-
packages/django/core/management/commands/migrate.py", line 160, in handle
executor.migrate(targets, plan, fake=options.get("fake", False))
File "/usr/lib/python3/dist-packages/django/db/migrations/executor.py",
line 63, in migrate
self.apply_migration(migration, fake=fake)
File "/usr/lib/python3/dist-packages/django/db/migrations/executor.py",
line 91, in apply_migration
if self.detect_soft_applied(migration):
File "/usr/lib/python3/dist-packages/django/db/migrations/executor.py",
line 135, in detect_soft_applied
apps = project_state.render()
File "/usr/lib/python3/dist-packages/django/db/migrations/state.py",
line 67, in render
model.render(self.apps)
File "/usr/lib/python3/dist-packages/django/db/migrations/state.py",
line 311, in render
body,
File "/usr/lib/python3/dist-packages/django/db/models/base.py", line
171, in __new__
new_class.add_to_class(obj_name, obj)
File "/usr/lib/python3/dist-packages/django/db/models/base.py", line
300, in add_to_class
value.contribute_to_class(cls, name)
File "/usr/lib/python3/dist-
packages/django/db/models/fields/related.py", line 2239, in
contribute_to_class
super(ManyToManyField, self).contribute_to_class(cls, name)
File "/usr/lib/python3/dist-
packages/django/db/models/fields/related.py", line 269, in
contribute_to_class
'app_label': cls._meta.app_label.lower()
TypeError: unsupported operand type(s) for %: 'bytes' and 'dict'
}}}
If I run makemigrations under Python 3, it does the correct thing:
{{{
migrations.AddField(
model_name='institute',
name='delegates',
field=models.ManyToManyField(related_name='delegate_for', null=True,
through='karaage.InstituteDelegate', to='karaage.Person', blank=True),
preserve_default=True,
),
}}}
If I look at a diff, it seems that just about everywhere a string (in the
above example, `through` and `to` appear to be ok) was used it is
incorrectly quoted in the migration as a byte string.
Apologies if this is already reported or documented somewhere, I looked
but couldn't see anything.
I have a vague recollection this may not have been a problem in the RC1
release, not absolutely sure now.
--
Ticket URL: <https://code.djangoproject.com/ticket/23455>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/048.53ebfe510d715bd09b5287fe94f862cf%40djangoproject.com.
For more options, visit https://groups.google.com/d/optout.
