Python: remove Verify and ./diagnostics (#287)

### Motivation and Context

In an effort to make the Python port more idiomatic, let's remove the
`Verify` class and the `./diagnostics` sub-module. There are many more
follow-on tasks to do here, but this is a good start (and already a
large enough change).

### Description

This PR does the following:

1. Removes the `Verify` class, and re-writes all instances of `Verify.*`
2. Adds a `validation.py` in the `./utils` sub-module to hand some of
the more complex cases from `Verify` (checking that skills/functions/and
function params have valid names)
3. Removes the rest of the `./diagnostics` sub-module (w/ a longer-term
goal of removing all/most of our custom exception classes and, instead,
using appropriate built-in error classes)

python/.env.example

@@ -1,4 +1,4 @@
 OPENAI_API_KEY=""
 OPENAI_ORG_ID=""
 AZURE_OPENAI_API_KEY=""
-AZURE_OPENAI_ENDPOINT=""
+AZURE_OPENAI_ENDPOINT=""

python/semantic_kernel/ai/ai_exception.py

@@ -3,10 +3,8 @@
 from enum import Enum
 from typing import Optional
 
-from semantic_kernel.diagnostics.sk_exception import SKException
 
-
-class AIException(SKException):
+class AIException(Exception):
     class ErrorCodes(Enum):
         # Unknown error.
         UnknownError = -1

python/semantic_kernel/ai/open_ai/services/azure_chat_completion.py

@@ -7,7 +7,6 @@
 from semantic_kernel.ai.open_ai.services.open_ai_chat_completion import (
     OpenAIChatCompletion,
 )
-from semantic_kernel.diagnostics.verify import Verify
 
 
 class AzureChatCompletion(OpenAIChatCompletion):
@@ -22,12 +21,14 @@ def __init__(
         api_version: str = "2023-03-15-preview",
         logger: Optional[Logger] = None,
     ) -> None:
-        Verify.not_empty(deployment_name, "You must provide a deployment name")
-        Verify.not_empty(api_key, "The Azure API key cannot be empty")
-        Verify.not_empty(endpoint, "The Azure endpoint cannot be empty")
-        Verify.starts_with(
-            endpoint, "https://", "The Azure endpoint must start with https://"
-        )
+        if not deployment_name:
+            raise ValueError("The deployment name cannot be `None` or empty")
+        if not api_key:
+            raise ValueError("The Azure API key cannot be `None` or empty`")
+        if not endpoint:
+            raise ValueError("The Azure endpoint cannot be `None` or empty")
+        if not endpoint.startswith("https://"):
+            raise ValueError("The Azure endpoint must start with https://")
 
         self._endpoint = endpoint
         self._api_version = api_version

python/semantic_kernel/ai/open_ai/services/azure_text_completion.py

@@ -7,7 +7,6 @@
 from semantic_kernel.ai.open_ai.services.open_ai_text_completion import (
     OpenAITextCompletion,
 )
-from semantic_kernel.diagnostics.verify import Verify
 
 
 class AzureTextCompletion(OpenAITextCompletion):
@@ -22,12 +21,14 @@ def __init__(
         api_version: str = "2022-12-01",
         logger: Optional[Logger] = None,
     ) -> None:
-        Verify.not_empty(deployment_name, "You must provide a deployment name")
-        Verify.not_empty(api_key, "The Azure API key cannot be empty")
-        Verify.not_empty(endpoint, "The Azure endpoint cannot be empty")
-        Verify.starts_with(
-            endpoint, "https://", "The Azure endpoint must start with https://"
-        )
+        if not deployment_name:
+            raise ValueError("The deployment name cannot be `None` or empty")
+        if not api_key:
+            raise ValueError("The Azure API key cannot be `None` or empty`")
+        if not endpoint:
+            raise ValueError("The Azure endpoint cannot be `None` or empty")
+        if not endpoint.startswith("https://"):
+            raise ValueError("The Azure endpoint must start with https://")
 
         self._endpoint = endpoint
         self._api_version = api_version

python/semantic_kernel/ai/open_ai/services/azure_text_embedding.py

@@ -7,7 +7,6 @@
 from semantic_kernel.ai.open_ai.services.open_ai_text_embedding import (
     OpenAITextEmbedding,
 )
-from semantic_kernel.diagnostics.verify import Verify
 
 
 class AzureTextEmbedding(OpenAITextEmbedding):
@@ -22,12 +21,14 @@ def __init__(
         api_version: str = "2022-12-01",
         logger: Optional[Logger] = None,
     ) -> None:
-        Verify.not_empty(deployment_name, "You must provide a deployment name")
-        Verify.not_empty(api_key, "The Azure API key cannot be empty")
-        Verify.not_empty(endpoint, "The Azure endpoint cannot be empty")
-        Verify.starts_with(
-            endpoint, "https://", "The Azure endpoint must start with https://"
-        )
+        if not deployment_name:
+            raise ValueError("The deployment name cannot be `None` or empty")
+        if not api_key:
+            raise ValueError("The Azure API key cannot be `None` or empty`")
+        if not endpoint:
+            raise ValueError("The Azure endpoint cannot be `None` or empty")
+        if not endpoint.startswith("https://"):
+            raise ValueError("The Azure endpoint must start with https://")
 
         self._endpoint = endpoint
         self._api_version = api_version

python/semantic_kernel/ai/open_ai/services/open_ai_chat_completion.py

@@ -6,7 +6,6 @@
 from semantic_kernel.ai.ai_exception import AIException
 from semantic_kernel.ai.chat_completion_client_base import ChatCompletionClientBase
 from semantic_kernel.ai.chat_request_settings import ChatRequestSettings
-from semantic_kernel.diagnostics.verify import Verify
 from semantic_kernel.utils.null_logger import NullLogger
 
 
@@ -65,7 +64,8 @@ async def complete_chat_async(
         Returns:
             str -- The completed text.
         """
-        Verify.not_null(request_settings, "The request settings cannot be empty")
+        if request_settings is None:
+            raise ValueError("The request settings cannot be `None`")
 
         if request_settings.max_tokens < 1:
             raise AIException(

python/semantic_kernel/ai/open_ai/services/open_ai_text_completion.py

@@ -6,7 +6,6 @@
 from semantic_kernel.ai.ai_exception import AIException
 from semantic_kernel.ai.complete_request_settings import CompleteRequestSettings
 from semantic_kernel.ai.text_completion_client_base import TextCompletionClientBase
-from semantic_kernel.diagnostics.verify import Verify
 from semantic_kernel.utils.null_logger import NullLogger
 
 
@@ -65,8 +64,10 @@ async def complete_simple_async(
         Returns:
             str -- The completed text.
         """
-        Verify.not_empty(prompt, "The prompt is empty")
-        Verify.not_null(request_settings, "The request settings cannot be empty")
+        if not prompt:
+            raise ValueError("The prompt cannot be `None` or empty")
+        if request_settings is None:
+            raise ValueError("The request settings cannot be `None`")
 
         if request_settings.max_tokens < 1:
             raise AIException(

python/semantic_kernel/core_skills/text_memory_skill.py

@@ -1,6 +1,5 @@
 # Copyright (c) Microsoft. All rights reserved.
 
-from semantic_kernel.diagnostics.verify import Verify
 from semantic_kernel.orchestration.sk_context import SKContext
 from semantic_kernel.skill_definition import sk_function, sk_function_context_parameter
 
@@ -44,19 +43,18 @@ async def recall_async(self, ask: str, context: SKContext) -> str:
         Returns:
             The nearest item from the memory store
         """
-        Verify.not_null(context.variables, "Context has no variables")
-        assert context.variables is not None  # for type checker
-        Verify.not_null(context.memory, "Context has no memory")
-        assert context.memory is not None  # for type checker
+        if context.variables is None:
+            raise ValueError("Context has no variables")
+        if context.memory is None:
+            raise ValueError("Context has no memory")
 
         collection = (
             context.variables[TextMemorySkill.COLLECTION_PARAM]
             if context.variables.contains_key(TextMemorySkill.COLLECTION_PARAM)
             else TextMemorySkill.DEFAULT_COLLECTION
         )
-        Verify.not_empty(
-            collection, "Memory collection not defined for TextMemorySkill"
-        )
+        if not collection:
+            raise ValueError("Memory collection not defined for TextMemorySkill")
 
         relevance = (
             context.variables[TextMemorySkill.RELEVANCE_PARAM]
@@ -104,26 +102,25 @@ async def save_async(self, text: str, context: SKContext):
             context -- Contains the 'collection' to save the information
                 and unique 'key' to associate with the information
         """
-        Verify.not_null(context.variables, "Context has no variables")
-        assert context.variables is not None  # for type checker
-        Verify.not_null(context.memory, "Context has no memory")
-        assert context.memory is not None  # for type checker
+        if context.variables is None:
+            raise ValueError("Context has no variables")
+        if context.memory is None:
+            raise ValueError("Context has no memory")
 
         collection = (
             context.variables[TextMemorySkill.COLLECTION_PARAM]
             if context.variables.contains_key(TextMemorySkill.COLLECTION_PARAM)
             else TextMemorySkill.DEFAULT_COLLECTION
         )
-        Verify.not_empty(
-            collection, "Memory collection not defined for TextMemorySkill"
-        )
+        if not collection:
+            raise ValueError("Memory collection not defined for TextMemorySkill")
 
         key = (
             context.variables[TextMemorySkill.KEY_PARAM]
             if context.variables.contains_key(TextMemorySkill.KEY_PARAM)
             else None
         )
-        Verify.not_empty(key, "Memory key not defined for TextMemorySkill")
-        assert key is not None  # for type checker
+        if not key:
+            raise ValueError("Memory key not defined for TextMemorySkill")
 
         await context.memory.save_information_async(collection, text=text, id=key)