Confusing error message when serializing set data type

[pcdinh]

What did you do?

In Python 3.8, I tried to serialize a Python dict whose value can be a set. ujson failed to dumps() it into a JSON string. It is expected. But the error message is quite confusing

Python 3.8.2 (default, Feb 26 2020, 02:56:10)
[GCC 7.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from ujson import dumps
>>> dumps(set())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: �0d is not JSON serializable

What did you expect to happen?

ujson should have better error message that helps debugging. Here is the error message in built-in json module

>>> from json import dumps
>>> dumps(set())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.8/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File "/usr/lib/python3.8/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python3.8/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/usr/lib/python3.8/json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type set is not JSON serializable

json module has much better error message

What versions are you using?

• OS: Ubuntu 18.04
• Python: 3.8.2
• UltraJSON: 2.0.1

from ujson import dumps
dumps(set())

[hugovk]

Thanks, this was fixed in #382 and released in UltraJSON 2.0.2:

Python 3.8.1 (v3.8.1:1b293b6006, Dec 18 2019, 14:08:53)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from ujson import dumps
>>> import ujson
>>> ujson.__version__
'2.0.3'
>>> ujson.dumps(set())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: set() is not JSON serializable