add azure openai (#26)

* add azure openai

* discribe missing env

* move azure condition to top

textgrad/engine/__init__.py

@@ -30,10 +30,15 @@ def get_engine(engine_name: str, **kwargs) -> EngineLM:
     if engine_name in __ENGINE_NAME_SHORTCUTS__:
         engine_name = __ENGINE_NAME_SHORTCUTS__[engine_name]
 
-    if "seed" in kwargs and engine_name not in ["gpt-4", "gpt-3.5"]:
+    if "seed" in kwargs and "gpt-4" not in engine_name and "gpt-3.5" not in engine_name and "gpt-35" not in engine_name:
         raise ValueError(f"Seed is currently supported only for OpenAI engines, not {engine_name}")
 
-    if (("gpt-4" in engine_name) or ("gpt-3.5" in engine_name)):
+    if engine_name.startswith("azure"):
+        from .openai import AzureChatOpenAI
+        # remove engine_name "azure-" prefix
+        engine_name = engine_name[6:]
+        return AzureChatOpenAI(model_string=engine_name, **kwargs)
+    elif (("gpt-4" in engine_name) or ("gpt-3.5" in engine_name)):
         from .openai import ChatOpenAI
         return ChatOpenAI(model_string=engine_name, is_multimodal=_check_if_multimodal(engine_name), **kwargs)
     elif "claude" in engine_name:

textgrad/engine/openai.py

@@ -1,5 +1,5 @@
 try:
-    from openai import OpenAI
+    from openai import OpenAI, AzureOpenAI
 except ImportError:
     raise ImportError("If you'd like to use OpenAI models, please install the openai package by running `pip install openai`, and add 'OPENAI_API_KEY' to your environment variables.")
 
@@ -138,3 +138,44 @@ def _generate_from_multiple_input(
         response_text = response.choices[0].message.content
         self._save_cache(cache_key, response_text)
         return response_text
+
+class AzureChatOpenAI(ChatOpenAI):
+    def __init__(
+        self,
+        model_string="gpt-35-turbo",
+        system_prompt=ChatOpenAI.DEFAULT_SYSTEM_PROMPT,
+        **kwargs):
+        """
+        Initializes an interface for interacting with Azure's OpenAI models.
+
+        This class extends the ChatOpenAI class to use Azure's OpenAI API instead of OpenAI's API. It sets up the necessary client with the appropriate API version, API key, and endpoint from environment variables.
+
+        :param model_string: The model identifier for Azure OpenAI. Defaults to 'gpt-3.5-turbo'.
+        :param system_prompt: The default system prompt to use when generating responses. Defaults to ChatOpenAI's default system prompt.
+        :param kwargs: Additional keyword arguments to pass to the ChatOpenAI constructor.
+
+        Environment variables:
+        - AZURE_OPENAI_API_KEY: The API key for authenticating with Azure OpenAI.
+        - AZURE_OPENAI_API_BASE: The base URL for the Azure OpenAI API.
+        - AZURE_OPENAI_API_VERSION: The API version to use. Defaults to '2023-07-01-preview' if not set.
+
+        Raises:
+            ValueError: If the AZURE_OPENAI_API_KEY environment variable is not set.
+        """
+        root = platformdirs.user_cache_dir("textgrad")
+        cache_path = os.path.join(root, f"cache_azure_{model_string}.db")  # Changed cache path to differentiate from OpenAI cache
+
+        super().__init__(cache_path=cache_path, system_prompt=system_prompt, **kwargs)
+
+        self.system_prompt = system_prompt
+        api_version = os.getenv("AZURE_OPENAI_API_VERSION", "2023-07-01-preview")
+        if os.getenv("AZURE_OPENAI_API_KEY") is None:
+            raise ValueError("Please set the AZURE_OPENAI_API_KEY, AZURE_OPENAI_API_BASE, and AZURE_OPENAI_API_VERSION environment variables if you'd like to use Azure OpenAI models.")
+
+        self.client = AzureOpenAI(
+            api_version=api_version,
+            api_key=os.getenv("AZURE_OPENAI_API_KEY"),
+            azure_endpoint=os.getenv("AZURE_OPENAI_API_BASE"),
+            azure_deployment=model_string,
+        )
+        self.model_string = model_string