Fix anthropic secret key when passed in via init (#11185)

Fixes anthropic secret key when passed via init

https://github.com/langchain-ai/langchain/issues/11182

libs/langchain/langchain/llms/anthropic.py

@@ -1,6 +1,16 @@
 import re
 import warnings
-from typing import Any, AsyncIterator, Callable, Dict, Iterator, List, Mapping, Optional
+from typing import (
+    Any,
+    AsyncIterator,
+    Callable,
+    Dict,
+    Iterator,
+    List,
+    Mapping,
+    Optional,
+    Union,
+)
 
 from langchain.callbacks.manager import (
     AsyncCallbackManagerForLLMRun,
@@ -19,6 +29,13 @@ from langchain.utils import (
 from langchain.utils.utils import build_extra_kwargs
 
 
+def _to_secret(value: Union[SecretStr, str]) -> SecretStr:
+    """Convert a string to a SecretStr if needed."""
+    if isinstance(value, SecretStr):
+        return value
+    return SecretStr(value)
+
+
 class _AnthropicCommon(BaseLanguageModel):
     client: Any = None  #: :meta private:
     async_client: Any = None  #: :meta private:
@@ -64,7 +81,7 @@ class _AnthropicCommon(BaseLanguageModel):
     @root_validator()
     def validate_environment(cls, values: Dict) -> Dict:
         """Validate that api key and python package exists in environment."""
-        values["anthropic_api_key"] = SecretStr(
+        values["anthropic_api_key"] = _to_secret(
             get_from_dict_or_env(values, "anthropic_api_key", "ANTHROPIC_API_KEY")
         )
         # Get custom api url from environment.

libs/langchain/tests/integration_tests/chat_models/test_anthropic.py

@@ -22,6 +22,13 @@ def test_anthropic_call() -> None:
     assert isinstance(response.content, str)
 
 
+def test_anthropic_initialization() -> None:
+    """Test anthropic initialization."""
+    # Verify that chat anthropic can be initialized using a secret key provided
+    # as a parameter rather than an environment variable.
+    ChatAnthropic(model="test", anthropic_api_key="test")
+
+
 def test_anthropic_generate() -> None:
     """Test generate method of anthropic."""
     chat = ChatAnthropic(model="test")