Add token parser for Bedrock & fix anthropic typo (#1851)

I am currently using Ragas with Bedrock and had to create new token
usage parsers. This PR responds to
[Issue-1151](#1151)

Thanks for this package it's nice 😄

src/ragas/cost.py

@@ -100,6 +100,33 @@ def get_token_usage_for_anthropic(
         return TokenUsage(input_tokens=0, output_tokens=0)
 
 
+def get_token_usage_for_bedrock(
+    llm_result: t.Union[LLMResult, ChatResult],
+) -> TokenUsage:
+    token_usages = []
+    for gs in llm_result.generations:
+        for g in gs:
+            if isinstance(g, ChatGeneration):
+                if g.message.response_metadata != {}:
+                    token_usages.append(
+                        TokenUsage(
+                            input_tokens=get_from_dict(
+                                g.message.response_metadata,
+                                "usage.prompt_tokens",
+                                0,
+                            ),
+                            output_tokens=get_from_dict(
+                                g.message.response_metadata,
+                                "usage.completion_tokens",
+                                0,
+                            ),
+                        )
+                    )
+
+        return sum(token_usages, TokenUsage(input_tokens=0, output_tokens=0))
+    return TokenUsage(input_tokens=0, output_tokens=0)
+
+
 class CostCallbackHandler(BaseCallbackHandler):
     def __init__(self, token_usage_parser: TokenUsageParser):
         self.token_usage_parser = token_usage_parser

src/ragas/integrations/swarm.py

@@ -1,5 +1,6 @@
 import json
 from typing import Any, Dict, List, Union
+
 from ragas.messages import AIMessage, HumanMessage, ToolCall, ToolMessage
 
 

src/ragas/llms/base.py

@@ -182,7 +182,7 @@ def is_finished(self, response: LLMResult) -> bool:
                 elif resp_message.response_metadata.get("stop_reason") is not None:
                     stop_reason = resp_message.response_metadata.get("stop_reason")
                     is_finished_list.append(
-                        stop_reason in ["end_turn", "STOP", "MAX_TOKENS"]
+                        stop_reason in ["end_turn", "stop", "STOP", "MAX_TOKENS"]
                     )
             # default to True
             else:

src/ragas/prompt/pydantic_prompt.py

@@ -1,11 +1,10 @@
 from __future__ import annotations
 
 import copy
+import hashlib
 import json
 import logging
 import os
-import hashlib
-
 import typing as t
 
 from langchain_core.exceptions import OutputParserException
@@ -228,7 +227,7 @@ async def adapt(
         """
         Adapt the prompt to a new language.
         """
-        
+
         strings = get_all_strings(self.examples)
         translated_strings = await translate_statements_prompt.generate(
             llm=llm,
@@ -275,7 +274,7 @@ def __str__(self):
             ensure_ascii=False,
         )[1:-1]
         return f"{self.__class__.__name__}({json_str})"
-        
+
     def __hash__(self):
         # convert examples to json string for hashing
         examples = []
@@ -284,23 +283,23 @@ def __hash__(self):
             examples.append(
                 (input_model.model_dump_json(), output_model.model_dump_json())
             )
-    
+
         # create a SHA-256 hash object
         hasher = hashlib.sha256()
-    
+
         # update the hash object with the bytes of each attribute
-        hasher.update(self.name.encode('utf-8'))
-        hasher.update(self.input_model.__name__.encode('utf-8'))
-        hasher.update(self.output_model.__name__.encode('utf-8'))
-        hasher.update(self.instruction.encode('utf-8'))
+        hasher.update(self.name.encode("utf-8"))
+        hasher.update(self.input_model.__name__.encode("utf-8"))
+        hasher.update(self.output_model.__name__.encode("utf-8"))
+        hasher.update(self.instruction.encode("utf-8"))
         for example in examples:
-            hasher.update(example[0].encode('utf-8'))
-            hasher.update(example[1].encode('utf-8'))
-        hasher.update(self.language.encode('utf-8'))
-    
+            hasher.update(example[0].encode("utf-8"))
+            hasher.update(example[1].encode("utf-8"))
+        hasher.update(self.language.encode("utf-8"))
+
         # return the integer value of the hash
         return int(hasher.hexdigest(), 16)
-    
+
     def __eq__(self, other):
         if not isinstance(other, PydanticPrompt):
             return False

tests/unit/test_cost.py

@@ -6,6 +6,7 @@
     CostCallbackHandler,
     TokenUsage,
     get_token_usage_for_anthropic,
+    get_token_usage_for_bedrock,
     get_token_usage_for_openai,
 )
 
@@ -62,7 +63,7 @@ def test_token_usage_cost():
     },
 )
 
-athropic_llm_result = LLMResult(
+anthropic_llm_result = LLMResult(
     generations=[
         [
             ChatGeneration(
@@ -82,16 +83,70 @@ def test_token_usage_cost():
     llm_output={},
 )
 
+bedrock_llama_result = LLMResult(
+    generations=[
+        [
+            ChatGeneration(
+                text="Hello, world!",
+                message=AIMessage(
+                    content="Hello, world!",
+                    response_metadata={
+                        "usage": {
+                            "prompt_tokens": 10,
+                            "completion_tokens": 10,
+                            "total_tokens": 20,
+                        },
+                        "stop_reason": "stop",
+                        "model_id": "us.meta.llama3-1-70b-instruct-v1:0",
+                    },
+                ),
+            )
+        ]
+    ],
+    llm_output={},
+)
+
+bedrock_claude_result = LLMResult(
+    generations=[
+        [
+            ChatGeneration(
+                text="Hello, world!",
+                message=AIMessage(
+                    content="Hello, world!",
+                    response_metadata={
+                        "usage": {
+                            "prompt_tokens": 10,
+                            "completion_tokens": 10,
+                            "total_tokens": 20,
+                        },
+                        "stop_reason": "end_turn",
+                        "model_id": "us.anthropic.claude-3-5-sonnet-20240620-v1:0",
+                    },
+                ),
+            )
+        ]
+    ],
+    llm_output={},
+)
+
 
 def test_parse_llm_results():
     # openai
     token_usage = get_token_usage_for_openai(openai_llm_result)
     assert token_usage == TokenUsage(input_tokens=10, output_tokens=10)
 
     # anthropic
-    token_usage = get_token_usage_for_anthropic(athropic_llm_result)
+    token_usage = get_token_usage_for_anthropic(anthropic_llm_result)
     assert token_usage == TokenUsage(input_tokens=9, output_tokens=12)
 
+    # Bedrock LLaMa
+    token_usage = get_token_usage_for_bedrock(bedrock_llama_result)
+    assert token_usage == TokenUsage(input_tokens=10, output_tokens=10)
+
+    # Bedrock Claude
+    token_usage = get_token_usage_for_bedrock(bedrock_claude_result)
+    assert token_usage == TokenUsage(input_tokens=10, output_tokens=10)
+
 
 def test_cost_callback_handler():
     cost_cb = CostCallbackHandler(token_usage_parser=get_token_usage_for_openai)