Support for IpAddress

[samuelcolvin]

Feature Request

https://docs.python.org/3/library/ipaddress.html

Both the stdlib IPv4Address and IPv6Address should work out of the box, also I guess IPAddress or IPvXAddress class will have to be included in pydantic which allows both v4 and v6 addresses. I guess this should inherit from _BaseAddress in Lib/ipaddress.py

[samuelcolvin]

I guess IPv4Network and IPv4Interface and their v6 equivalents should also be supported.

This would be a great issue for anyone new keen to contribute to pydantic.

[pilosus]

@samuelcolvin
#417 implements IPv4Address and IPv6Address but doesn't support networks and interfaces from ipaddress. I've been working on the networks and interfaces. Please, let me know if I should submit a PR once networks and interfaces are completed or their support's no longer needed.

[samuelcolvin]

yes please, reopened this.

[haizaar]

Is json serialization supposed to work for this field? Is it just a matter of adding it to ENCODERS_BY_TYPE?

$ pip freeze |grep pydantic
pydantic==0.22
$ cat /tmp/my.py
from pydantic import BaseModel
from ipaddress import IPv4Address

class Model(BaseModel):
    ip: IPv4Address

Model(ip="127.0.0.1").json()
$ python /tmp/my.py
Traceback (most recent call last):
  File "/home/.../python3.7/site-packages/pydantic/json.py", line 38, in pydantic_encoder
    encoder = ENCODERS_BY_TYPE[type(obj)]
KeyError: <class 'ipaddress.IPv4Address'>

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/tmp/my.py", line 9, in <module>
    Model(ip="127.0.0.1").json()
  File "/home/.../python3.7/site-packages/pydantic/main.py", line 308, in json
    **dumps_kwargs,
  File "/usr/lib/python3.7/json/__init__.py", line 238, in dumps
    **kw).encode(obj)
  File "/usr/lib/python3.7/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python3.7/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/home/.../python3.7/site-packages/pydantic/json.py", line 40, in pydantic_encoder
    raise TypeError(f"Object of type '{obj.__class__.__name__}' is not JSON serializable")
TypeError: Object of type 'IPv4Address' is not JSON serializable

[pilosus]

ipaddress address, interface and network object are indeed not serializable by default, they should be converted to str. I personally think we should support this conversion just like we do for UUID objects.
Yes, extending ENCODERS_BY_TYPE with these keys will solve the problem:

ENCODERS_BY_TYPE: Dict[Type[Any], Callable[[Any], Any]] = {
    IPv4Address: str,
    IPv6Address: str,
    IPv4Interface: str,
    IPv6Interface: str,
    IPv4Network: str,
    IPv6Network: str,
    ...

Unittests to tests/test_json.py should also be added.
@samuelcolvin I'm not sure if a new issue should be open or it's okay to use this one. Anyway, If my help needed, please tag me, I'll fix serialization in a matter a few hours.

[samuelcolvin]

Yes should be supported.

@pilosus would be great if you could do this.