UUID('...') is not JSON serializable
PythonDjangoUuidPython Problem Overview
I get this error when i try to pass the UUID attribute to url parameter.
urlpatterns = [
url(r'^historia-clinica/(?P<uuid>[W\d\-]+)/$', ClinicHistoryDetail.as_view(), name='...'),
]
views.py
class ClinicHistoryDetail(...):
...
my_object = MyModel.objects.create(...)
...
return redirect(reverse('namespace:name', kwargs={'uuid' : my_object.id}))
model.py
class MyModel(models.Model):
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
...
Any suggestions?
Python Solutions
Solution 1 - Python
There is a bug ticket on Django regarding this issue however a custom so called 'complex encoder' by python docs can help you.
import json
from uuid import UUID
class UUIDEncoder(json.JSONEncoder):
def default(self, obj):
if isinstance(obj, UUID):
# if the obj is uuid, we simply return the value of uuid
return obj.hex
return json.JSONEncoder.default(self, obj)
Now if we did something like this
json.dumps(my_object, cls=UUIDEncoder)
Your uuid field should be encoded.
Solution 2 - Python
Convert UUID to str.
uuid_str = str(uuid_item)
Solution 3 - Python
For using the UUID in a URL like that, you should pass it as a string:
return redirect(reverse('namespace:name', kwargs={'uuid' : str(object.id)}))
FYI - it looks like WIMs answer is a bit more thorough. Your regex should certainly be tightened up. If you end up using the string representation of the slug, you'll want a regex like this: [A-Za-z0-9\-]+
which allows for alphanumerics and hyphens.
Solution 4 - Python
I use convert function for this, it is simple and clean.
import json
from uuid import UUID
def uuid_convert(o):
if isinstance(o, UUID):
return o.hex
json.dumps(users,indent=4,default=uuid_convert)
Solution 5 - Python
Looks like this error is no more relevant for django, while using DjangoJSONEncoder
. No need to write own custom encoder. Provided by django handles most known serializing problems.
import json
from django.core.serializers.json import DjangoJSONEncoder
json.dumps(my_object, cls=DjangoJSONEncoder)
Details here
Solution 6 - Python
I had this same problem with a UUID field in a database model that I wanted to print out for debugging. I found that the pprint()
function from the pprint
module can handle this. You can also give it an indent
argument to get the same kind of indented output that you would get from json.dumps()
https://docs.python.org/3/library/pprint.html#pprint.pprint
Example:
>>> import uuid
>>> import pprint
>>> import json
>>> x = uuid.UUID('12345678123456781234567812345678')
>>> x
UUID('12345678-1234-5678-1234-567812345678')
>>> print(x)
12345678-1234-5678-1234-567812345678
>>> json.dumps(x)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
...
...
raise TypeError(repr(o) + " is not JSON serializable")
TypeError: UUID('12345678-1234-5678-1234-567812345678') is not JSON serializable
>>> pprint.pprint(x)
UUID('12345678-1234-5678-1234-567812345678')