feat(minor): Allow passing config to parse_obj_as

[gavindsouza]

The parse_obj_as API doesn't allow arbitrary objects which can be extended by passing Config. My use case is similar to this question @samuelcolvin has answered on SO.

# before - ohno runtime error I can probably do nothing about ༼ಢ_ಢ༽ 
In [1]: parse_obj_as(list[File], 'true')
---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
File <ipython-input-7-4e10774d8e55>:1, in <cell line: 1>()
----> 1 parse_obj_as(list[File], 'true')
File ~/Desktop/projects-bench/env/lib/python3.10/site-packages/pydantic/tools.py:30, in pydantic.tools._get_parsing_type()
File ~/Desktop/projects-bench/env/lib/python3.10/site-packages/pydantic/main.py:1026, in pydantic.main.create_model()
File ~/Desktop/projects-bench/env/lib/python3.10/site-packages/pydantic/main.py:198, in pydantic.main.ModelMetaclass.__new__()
File ~/Desktop/projects-bench/env/lib/python3.10/site-packages/pydantic/fields.py:506, in pydantic.fields.ModelField.infer()
File ~/Desktop/projects-bench/env/lib/python3.10/site-packages/pydantic/fields.py:436, in pydantic.fields.ModelField.__init__()
File ~/Desktop/projects-bench/env/lib/python3.10/site-packages/pydantic/fields.py:557, in pydantic.fields.ModelField.prepare()
File ~/Desktop/projects-bench/env/lib/python3.10/site-packages/pydantic/fields.py:831, in pydantic.fields.ModelField.populate_validators()
File ~/Desktop/projects-bench/env/lib/python3.10/site-packages/pydantic/validators.py:765, in find_validators()
RuntimeError: no validator found for <class 'frappe.core.doctype.file.file.File'>, see `arbitrary_types_allowed` in Config

# after - works as expected ヽ(^ᴗ^ヽ)
In [2]: parse_obj_as(list[File], 'true', config=FrappePydanticConfig)
---------------------------------------------------------------------------
ValidationError                           Traceback (most recent call last)
File <ipython-input-12-268e8a88311f>:1, in <cell line: 1>()
----> 1 parse_obj_as(list[File], 'true', config=FrappePydanticConfig)

File ~/Desktop/projects-bench/apps/frappe/frappe/utils/typing_validations.py:76, in parse_obj_as(type_, obj, type_name, config)
     67 def parse_obj_as(
     68 	type_: type[T],
     69 	obj: Any,
   (...)
     73 ) -> T:
     74 	# Note: This is a copy of pydantic.tools.parse_obj_as with the addition of allowing a config argument
     75 	model_type = _get_parsing_type(type_, type_name=type_name, config=config)  # type: ignore[arg-type]
---> 76 	return model_type(__root__=obj).__root__

File ~/Desktop/projects-bench/env/lib/python3.10/site-packages/pydantic/main.py:342, in pydantic.main.BaseModel.__init__()

ValidationError: 1 validation error for ParsingModel[list[frappe.core.doctype.file.file.File]]
__root__
  value is not a valid list (type=type_error.list)

[hramezani]

Thanks @gavindsouza for this 👍

I am not sure whether we want to accept this. but you need to:

• Add test for your change
• Update parse_obj_as documentation and examples

@samuelcolvin what do you think about this?

[gavindsouza]

I hope this change is accepted if parse_obj_as is to be considered a public API. I've currently had to redefine _get_parsing_type and parse_obj_as in frappe/frappe@f7c5b40.

Will add a test and update docs if this change is acceptable @hramezani. (Also, thank you for your good work :D)

[samuelcolvin]

hi @gavindsouza thanks so much for the contribution, parse_obj_as will be removed in V2 and replaced by the generic validate method, see #4669. Hence it's not really worth your effort to finish this as it'll get deleted just as soon as I get serialisation in rust finished and get onto this.

If you have feedback on the API, best to add it there to #4669. But we will definitely need to allow config to be set with validate(), see also #4673.