principles list (#1888)

langchain/chains/constitutional_ai/base.py

@@ -1,8 +1,9 @@
 """Chain for applying constitutional principles to the outputs of another chain."""
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Optional
 
 from langchain.chains.base import Chain
 from langchain.chains.constitutional_ai.models import ConstitutionalPrinciple
+from langchain.chains.constitutional_ai.principles import PRINCIPLES
 from langchain.chains.constitutional_ai.prompts import CRITIQUE_PROMPT, REVISION_PROMPT
 from langchain.chains.llm import LLMChain
 from langchain.prompts.base import BasePromptTemplate
@@ -42,6 +43,15 @@ class ConstitutionalChain(Chain):
     critique_chain: LLMChain
     revision_chain: LLMChain
 
+    @classmethod
+    def get_principles(
+        cls, names: Optional[List[str]] = None
+    ) -> List[ConstitutionalPrinciple]:
+        if names is None:
+            return list(PRINCIPLES.values())
+        else:
+            return [PRINCIPLES[name] for name in names]
+
     @classmethod
     def from_llm(
         cls,

langchain/chains/constitutional_ai/principles.py

@@ -0,0 +1,5 @@
+# flake8: noqa
+from typing import Dict
+from langchain.chains.constitutional_ai.models import ConstitutionalPrinciple
+
+PRINCIPLES: Dict[str, ConstitutionalPrinciple] = {}