experimental[patch]: Migrate pydantic extra to literals (#25194)

Migrate pydantic extra to literals

Upgrade to using a literal for specifying the extra which is the
recommended approach in pydantic 2.

This works correctly also in pydantic v1.

```python
from pydantic.v1 import BaseModel

class Foo(BaseModel, extra="forbid"):
    x: int

Foo(x=5, y=1)
```

And 


```python
from pydantic.v1 import BaseModel

class Foo(BaseModel):
    x: int

    class Config:
      extra = "forbid"

Foo(x=5, y=1)
```


## Enum -> literal using grit pattern:

```
engine marzano(0.1)
language python
or {
    `extra=Extra.allow` => `extra="allow"`,
    `extra=Extra.forbid` => `extra="forbid"`,
    `extra=Extra.ignore` => `extra="ignore"`
}
```

Resorted attributes in config and removed doc-string in case we will
need to deal with going back and forth between pydantic v1 and v2 during
the 0.3 release. (This will reduce merge conflicts.)


## Sort attributes in Config:

```
engine marzano(0.1)
language python


function sort($values) js {
    return $values.text.split(',').sort().join("\n");
}


class_definition($name, $body) as $C where {
    $name <: `Config`,
    $body <: block($statements),
    $values = [],
    $statements <: some bubble($values) assignment() as $A where {
        $values += $A
    },
    $body => sort($values),
}

```

libs/experimental/langchain_experimental/autonomous_agents/baby_agi/baby_agi.py

@@ -52,8 +52,6 @@ class BabyAGI(Chain, BaseModel):  # type: ignore[misc]
     max_iterations: Optional[int] = None
 
     class Config:
-        """Configuration for this pydantic object."""
-
         arbitrary_types_allowed = True
 
     def add_task(self, task: Dict) -> None:

libs/experimental/langchain_experimental/generative_agents/generative_agent.py

@@ -36,8 +36,6 @@ class GenerativeAgent(BaseModel):
     """Summary of the events in the plan that the agent took."""
 
     class Config:
-        """Configuration for this pydantic object."""
-
         arbitrary_types_allowed = True
 
     # LLM-related methods

libs/experimental/langchain_experimental/llm_bash/base.py

@@ -14,7 +14,7 @@ from langchain_core.language_models import BaseLanguageModel
 
 from langchain_experimental.llm_bash.bash import BashProcess
 from langchain_experimental.llm_bash.prompt import PROMPT
-from langchain_experimental.pydantic_v1 import Extra, Field, root_validator
+from langchain_experimental.pydantic_v1 import Field, root_validator
 
 logger = logging.getLogger(__name__)
 
@@ -40,10 +40,8 @@ class LLMBashChain(Chain):
     bash_process: BashProcess = Field(default_factory=BashProcess)  #: :meta private:
 
     class Config:
-        """Configuration for this pydantic object."""
-
-        extra = Extra.forbid
         arbitrary_types_allowed = True
+        extra = "forbid"
 
     @root_validator(pre=True)
     def raise_deprecation(cls, values: Dict) -> Dict:

libs/experimental/langchain_experimental/llm_symbolic_math/base.py

@@ -15,7 +15,6 @@ from langchain_core.callbacks.manager import (
 from langchain_core.prompts.base import BasePromptTemplate
 
 from langchain_experimental.llm_symbolic_math.prompt import PROMPT
-from langchain_experimental.pydantic_v1 import Extra
 
 
 class LLMSymbolicMathChain(Chain):
@@ -38,10 +37,8 @@ class LLMSymbolicMathChain(Chain):
     output_key: str = "answer"  #: :meta private:
 
     class Config:
-        """Configuration for this pydantic object."""
-
-        extra = Extra.forbid
         arbitrary_types_allowed = True
+        extra = "forbid"
 
     @property
     def input_keys(self) -> List[str]:

libs/experimental/langchain_experimental/pal_chain/base.py

@@ -17,7 +17,7 @@ from langchain_core.language_models import BaseLanguageModel
 
 from langchain_experimental.pal_chain.colored_object_prompt import COLORED_OBJECT_PROMPT
 from langchain_experimental.pal_chain.math_prompt import MATH_PROMPT
-from langchain_experimental.pydantic_v1 import Extra, Field, root_validator
+from langchain_experimental.pydantic_v1 import Field, root_validator
 from langchain_experimental.utilities import PythonREPL
 
 COMMAND_EXECUTION_FUNCTIONS = [
@@ -169,10 +169,8 @@ class PALChain(Chain):
         return values
 
     class Config:
-        """Configuration for this pydantic object."""
-
-        extra = Extra.forbid
         arbitrary_types_allowed = True
+        extra = "forbid"
 
     @property
     def input_keys(self) -> List[str]:

libs/experimental/langchain_experimental/rl_chain/base.py

@@ -26,7 +26,7 @@ from langchain_core.prompts import (
     SystemMessagePromptTemplate,
 )
 
-from langchain_experimental.pydantic_v1 import BaseModel, Extra, root_validator
+from langchain_experimental.pydantic_v1 import BaseModel, root_validator
 from langchain_experimental.rl_chain.metrics import (
     MetricsTrackerAverage,
     MetricsTrackerRollingWindow,
@@ -417,10 +417,8 @@ class RLChain(Chain, Generic[TEvent]):
             self.metrics = MetricsTrackerAverage(step=metrics_step)
 
     class Config:
-        """Configuration for this pydantic object."""
-
-        extra = Extra.forbid
         arbitrary_types_allowed = True
+        extra = "forbid"
 
     @property
     def input_keys(self) -> List[str]:

libs/experimental/langchain_experimental/smart_llm/base.py

@@ -15,7 +15,7 @@ from langchain_core.prompts.chat import (
     HumanMessagePromptTemplate,
 )
 
-from langchain_experimental.pydantic_v1 import Extra, root_validator
+from langchain_experimental.pydantic_v1 import root_validator
 
 
 class SmartLLMChain(Chain):
@@ -84,7 +84,7 @@ class SmartLLMChain(Chain):
     history: SmartLLMChainHistory = SmartLLMChainHistory()
 
     class Config:
-        extra = Extra.forbid
+        extra = "forbid"
 
     # TODO: move away from `root_validator` since it is deprecated in pydantic v2
     #       and causes mypy type-checking failures (hence the `type: ignore`)

libs/experimental/langchain_experimental/sql/base.py

@@ -15,7 +15,7 @@ from langchain_core.callbacks.manager import CallbackManagerForChainRun
 from langchain_core.language_models import BaseLanguageModel
 from langchain_core.prompts.prompt import PromptTemplate
 
-from langchain_experimental.pydantic_v1 import Extra, Field, root_validator
+from langchain_experimental.pydantic_v1 import Field, root_validator
 
 INTERMEDIATE_STEPS_KEY = "intermediate_steps"
 SQL_QUERY = "SQLQuery:"
@@ -67,10 +67,8 @@ class SQLDatabaseChain(Chain):
     """The prompt template that should be used by the query checker"""
 
     class Config:
-        """Configuration for this pydantic object."""
-
-        extra = Extra.forbid
         arbitrary_types_allowed = True
+        extra = "forbid"
 
     @root_validator(pre=True)
     def raise_deprecation(cls, values: Dict) -> Dict:

libs/experimental/langchain_experimental/tot/base.py

@@ -10,7 +10,6 @@ from langchain_core.callbacks.manager import (
     CallbackManagerForChainRun,
 )
 
-from langchain_experimental.pydantic_v1 import Extra
 from langchain_experimental.tot.checker import ToTChecker
 from langchain_experimental.tot.controller import ToTController
 from langchain_experimental.tot.memory import ToTDFSMemory
@@ -44,10 +43,8 @@ class ToTChain(Chain):
     verbose_llm: bool = False
 
     class Config:
-        """Configuration for this pydantic object."""
-
-        extra = Extra.forbid
         arbitrary_types_allowed = True
+        extra = "forbid"
 
     @classmethod
     def from_llm(cls, llm: BaseLanguageModel, **kwargs: Any) -> ToTChain:

libs/experimental/langchain_experimental/video_captioning/base.py

@@ -4,7 +4,6 @@ from langchain.chains.base import Chain
 from langchain_core.callbacks import CallbackManagerForChainRun
 from langchain_core.language_models import BaseLanguageModel
 from langchain_core.prompts import PromptTemplate
-from langchain_core.pydantic_v1 import Extra
 
 from langchain_experimental.video_captioning.services.audio_service import (
     AudioProcessor,
@@ -38,8 +37,8 @@ class VideoCaptioningChain(Chain):
     use_unclustered_video_models: bool = False
 
     class Config:
-        extra = Extra.allow
         arbitrary_types_allowed = True
+        extra = "allow"
 
     @property
     def input_keys(self) -> List[str]: