sending json with Decimal

[dreinon]

Hi!
I would like to know if in the json parameter of a request, I'm allow to pass a dictionary one value of which is a decimal.Decimal, where decimal is the module from Python standard library.
If this json is stringified, it makes sense since the following assertion is true:

from decimal import Decimal
example_num = '2.3'
assert example_num == str(Decimal(example_num))

[agammann]

HTTPX's json= serialization does not automatically call str() on unsupported values. With HTTPX 0.28.1, a Decimal in the payload raises TypeError: Object of type Decimal is not JSON serializable.

If your API accepts a decimal as a JSON string, convert it explicitly before passing the payload:

from decimal import Decimal

payload = {"value": str(Decimal("2.3"))}
response = client.post(url, json=payload)

That sends {"value":"2.3"}: the value is a JSON string, not a JSON number. I tested both the error and explicit conversion with HTTPX 0.28.1. If the API requires a number, you'll need a representation/serializer that matches that requirement. See sending JSON data.