fix: openai env var load after init and before score also (#316)

Author: jjmachan

src/ragas/embeddings/base.py

@@ -40,7 +40,11 @@ def __init__(self, api_key: str = NO_KEY):
 
     def validate_api_key(self):
         if self.openai_api_key == NO_KEY:
-            raise OpenAIKeyNotFound
+            os_env_key = os.getenv("OPENAI_API_KEY", NO_KEY)
+            if os_env_key != NO_KEY:
+                self.api_key = os_env_key
+            else:
+                raise OpenAIKeyNotFound
 
 
 class AzureOpenAIEmbeddings(BaseAzureOpenAIEmbeddings, RagasEmbeddings):
@@ -73,7 +77,11 @@ def __init__(
 
     def validate_api_key(self):
         if self.openai_api_key == NO_KEY:
-            raise AzureOpenAIKeyNotFound
+            os_env_key = os.getenv("AZURE_OPENAI_API_KEY", NO_KEY)
+            if os_env_key != NO_KEY:
+                self.api_key = os_env_key
+            else:
+                raise AzureOpenAIKeyNotFound
 
 
 @dataclass

src/ragas/llms/openai.py

@@ -196,7 +196,11 @@ def validate_api_key(self):
         if api_key != NO_KEY:
             self._client.api_key = api_key
         if self.llm.api_key == NO_KEY:
-            raise OpenAIKeyNotFound
+            os_env_key = os.getenv(self._api_key_env_var, NO_KEY)
+            if os_env_key != NO_KEY:
+                self.api_key = os_env_key
+            else:
+                raise OpenAIKeyNotFound
 
 
 @dataclass
@@ -221,4 +225,8 @@ def _client_init(self):
 
     def validate_api_key(self):
         if self.llm.api_key == NO_KEY:
-            raise AzureOpenAIKeyNotFound
+            os_env_key = os.getenv(self._api_key_env_var, NO_KEY)
+            if os_env_key != NO_KEY:
+                self.api_key = os_env_key
+            else:
+                raise AzureOpenAIKeyNotFound

tests/unit/test_llm.py

@@ -136,3 +136,11 @@ def test_validate_api_key_for_different_llms(
     obj, api_key = factory(with_api_key=True)
     assert obj.validate_api_key
     assert obj.api_key == api_key
+
+    # assert loading key from environment variables after instantiation
+    if environ_key in os.environ:
+        os.environ.pop(environ_key)
+    obj = factory(with_api_key=False)
+    os.environ[environ_key] = "random-key-102848595"
+    assert obj.validate_api_key() is None
+    assert obj.api_key == "random-key-102848595"