updated config module and .env.example notes (#32)

examples/python-example01/.env.example

@@ -1,5 +1,9 @@
 # Description: Example of .env file
 # Usage: Copy this file to .env and set the values
 
+# NOTE: Changes to this file will not take effect until the project service is 'stopped' and 'started'
+# It is not enough to just use the VS Code 'restart' button
+
+# Assistant Service
 # The ASSISTANT__ prefix is used to group all the environment variables related to the assistant service.
 ASSISTANT__ENABLE_DEBUG_OUTPUT=True

semantic-workbench/v1/service/.env.example

@@ -1,9 +1,9 @@
-# Workflow Service
-WORKFLOW__AZURE_OPENAI_ENDPOINT=https://<YOUR-RESOURCE-NAME>.openai.azure.com/
-WORKFLOW__AZURE_OPENAI_API_KEY=...
+# This file contains the environment variables for the project
+
+# NOTE: Changes to this file will not take effect until the project service is 'stopped' and 'started'
+# It is not enough to just use the VS Code 'restart' button
 
-# Assistant Service
-ASSISTANT__AZURE_OPENAI_EMBEDDINGS_ENDPOINT=https://<YOUR-RESOURCE-NAME>.openai.azure.com/
-ASSISTANT__AZURE_OPENAI_EMBEDDINGS_KEY=...
-ASSISTANT__AZURE_OPENAI_ENDPOINT=https://<YOUR-RESOURCE-NAME>.openai.azure.com/
-ASSISTANT__AZURE_OPENAI_API_KEY=...
+# Workflow Service
+# NOTE: This feature is currently disabled, so no environment variables are needed
+# WORKFLOW__AZURE_OPENAI_ENDPOINT=https://<YOUR-RESOURCE-NAME>.openai.azure.com/
+# WORKFLOW__AZURE_OPENAI_API_KEY=...

semantic-workbench/v1/service/semantic-workbench-assistant/semantic_workbench_assistant/config.py

@@ -85,24 +85,39 @@ def callback_url(self) -> str:
 
 ModelT = TypeVar("ModelT", bound=BaseModel)
 
-_dotenv_values = dotenv.dotenv_values()
-
 
 def first_env_var(*env_vars: str, include_dotenv: bool = True, include_upper_and_lower: bool = True) -> str | None:
-    def first_not_none(*vals: str | None) -> str | None:
-        for val in vals:
-            if val is not None:
-                return val
-        return None
-
+    """
+    Get the first environment variable that is set. If include_dotenv is True, then
+    the dotenv values will be checked as well. If include_upper_and_lower is True,
+    then the upper and lower case versions of the env vars will also be checked.
+
+    .. warning::
+        The dotenv values may be cached in the environment, so if you have loaded
+        a .env file into the environment, you may need to 'stop' and then 'start' the
+        service to get the new values from the .env file. Using the 'restart' command
+        does not seem to work.
+    """
     if include_upper_and_lower:
         env_vars = (*env_vars, *[env_var.upper() for env_var in env_vars], *[env_var.lower() for env_var in env_vars])
 
-    env_values = [os.environ.get(env_var) for env_var in env_vars]
+    dotenv_values = {}
+    # load dotenv values if requested
     if include_dotenv:
-        env_values = [*[_dotenv_values.get(env_var) for env_var in env_vars], *env_values]
+        dotenv_values = dotenv.dotenv_values()
+
+    # check for the first env var that is set
+    # prioritize the environment over dotenv values
+    for env_var in env_vars:
+        # check for the env var in the environment
+        if env_var in os.environ:
+            return os.environ[env_var]
+
+        # check for the env var in the dotenv values
+        if env_var in dotenv_values:
+            return dotenv_values[env_var]
 
-    return first_not_none(*env_values)
+    return None
 
 
 def overwrite_defaults_from_env(model: ModelT, prefix="", separator="__") -> ModelT: