IrreversibleError is a class within the django.db.migrations.exceptions module of the Django project.
django-cms (project website) is a Python-based content management system (CMS) library for use with Django web apps that is open sourced under the BSD 3-Clause "New" license.
django-cms / cms / migrations / init.py
# __init__.py
from django.db import migrations
try:
IrreversibleError = migrations.Migration.IrreversibleError
except AttributeError:
from django.db.migrations.exceptions import IrreversibleError
class IrreversibleMigration(migrations.Migration):
def unapply(self, project_state, schema_editor, collect_sql=False):
raise IrreversibleError('Migration %s is not reversible' % self.name)
## ... source file continues with no further IrreversibleError examples...