dataclass with methods cannot use init=False fields

[toslunar]

Initial Checks

• I have searched GitHub for a duplicate issue and I'm sure this is something new
• I have searched Google & StackOverflow for a solution and couldn't find anything
• I have read and followed the docs and still think this is a bug
• I am confident that the issue is with pydantic (not my code, or another library in the ecosystem like FastAPI or mypy)

Description

Since pydantic 1.10.2, it fails to parse a builtin dataclass dataclass.field(init=False) if it has at least one method.
Similarly to #4498, the cause seems this change in #4484.

Example Code

import dataclasses
import pydantic

@dataclasses.dataclass
class Ok:
    a: int
    b: str = "b"
    c: float = dataclasses.field(init=False)

    def __post_init__(self):
        self.c = float(self.a)

@dataclasses.dataclass
class NotOkSince1_10_2:
    a: int
    b: str = "b"
    c: float = dataclasses.field(init=False)

    def __post_init__(self):
        self.c = float(self.a)

    @pydantic.validator("b")
    def check_b(cls, v):
        if not v:
            raise ValueError("b should not be empty")
        return v

    # ... or with a non-validator method
    # def foo(self):
    #     print("foo")


print(pydantic.parse_obj_as(Ok, {"a": 3}))  # Ok(a=3, b='b', c=3.0)
print(pydantic.parse_obj_as(NotOkSince1_10_2, {"a": 3}))  # TypeError: non-default argument 'c' follows default argument

Python, Pydantic & OS Version

pydantic version: 1.10.2
            pydantic compiled: True
                 install path: /Users/tos/.pyenv/versions/3.10.0/envs/p10/lib/python3.10/site-packages/pydantic
               python version: 3.10.0 (default, Oct 26 2021, 11:19:32) [Clang 11.0.0 (clang-1100.0.33.16)]
                     platform: macOS-11.7-x86_64-i386-64bit
     optional deps. installed: ['typing-extensions']

Affected Components

• Compatibility between releases
• Data validation/parsing
• Data serialization - .dict() and .json()
• JSON Schema
• Dataclasses
• Model Config
• Field Types - adding or changing a particular data type
• Function validation decorator
• Generic Models
• Other Model behaviour - construct(), pickling, private attributes, ORM mode
• Plugins and integration with other tools - mypy, FastAPI, python-devtools, Hypothesis, VS Code, PyCharm, etc.

[samuelcolvin]

@PrettyWood, any idea on this?

My instinct is that we have to call this a limitation of pydantic v1.10 and fix in v2.

[PrettyWood]

This will be fixed in 1.10.3

[samuelcolvin]

Closed via #4878