Get django-reversion to work with django-money

src/ralph/__init__.py

@@ -1,4 +1,3 @@
-from django.core import serializers
 from django.db.models.options import Options
 
 __version__ = '3.0.0'
@@ -13,5 +12,3 @@ def monkey_options_init(self, meta, app_label):
 Options.__init__ = lambda self, meta, app_label=None: monkey_options_init(
     self, meta, app_label
 )
-
-serializers.register_serializer("json", "ralph.lib.serializers")

src/ralph/apps.py

@@ -2,6 +2,7 @@
 from importlib import import_module
 
 from django.apps import AppConfig
+from django.core import serializers
 
 
 class RalphAppConfig(AppConfig):
@@ -15,6 +16,8 @@ def ready(self):
         """
         super().ready()
 
+        serializers.register_serializer("json", "ralph.lib.serializers")
+
         package = self.module.__name__
         for module in self.get_load_modules_when_ready():
             try:

src/ralph/lib/serializers/__init__.py

@@ -20,15 +20,17 @@ def Deserializer(stream_or_string, **options):  # noqa
     Deserialize a stream or string of JSON data.
     """
     # Copied almost without changes from djmoney.serializers (django-money).
-    # Adding support for situation where old models to be deserialized have price field,
-    # but not price_currency field.
-    # In Ralph, price field existed before in various models as a Decimal field.
-    # All price fields were migrated to MoneyField without changing the original field name.
-    # This can cause problems in original django-money's implementation of Deserializer.
-    # This updated Deserializer is needed to get revision (django-revision)
+    # Adding support for situation where old models to be deserialized have
+    # price field, but not price_currency field.
+    # In Ralph, price field existed before in various models as
+    # a Decimal field. All price fields were migrated to MoneyField
+    # without changing the original field name. This can cause problems
+    # in original django-money's implementation of Deserializer.
+    # This updated Deserializer is needed to get reversion (django-reversion)
     # to work in circumstances described above.
 
-    from django.core.serializers.python import Deserializer as PythonDeserializer, _get_model
+    from django.core.serializers.python import \
+        Deserializer as PythonDeserializer, _get_model
 
     ignore = options.pop("ignorenonexistent", False)
 
@@ -55,7 +57,8 @@ def Deserializer(stream_or_string, **options):  # noqa
                 field = Model._meta.get_field(field_name)
                 if isinstance(field, MoneyField) and field_value is not None:
                     try:
-                        currency = obj["fields"][get_currency_field_name(field_name)]
+                        currency = \
+                            obj["fields"][get_currency_field_name(field_name)]
                     except KeyError:
                         currency = DEFAULT_CURRENCY_CODE
                     money_fields[field_name] = Money(field_value, currency)
@@ -70,4 +73,6 @@ def Deserializer(stream_or_string, **options):  # noqa
     except (GeneratorExit, DeserializationError):
         raise
     except Exception as exc:
-        six.reraise(DeserializationError, DeserializationError(exc), sys.exc_info()[2])
+        six.reraise(
+            DeserializationError, DeserializationError(exc), sys.exc_info()[2]
+        )