Remove kernel builder pattern for Python: sk.kernel_create() -> sk.Ke…

…rnel() (#454)

### Motivation and Context

This PR makes creating a kernel instance more pythonic. The builder
pattern is removed and the kernel is constructed using Kernel(...).

Work originally started with #137

### Description

- Removed kernel_builder.py.
- Instance creation pattern `kernel = sk.create_kernel() -> kernel =
sk.Kernel()`
- For notebook 6, there is no need to create a separate kernel for the
GitHub files. Changed to use a separate collection.


Co-authored-by: Devis Lucato <dluc@users.noreply.github.com>

python/DEV_SETUP.md

@@ -98,7 +98,7 @@ You should be able to run the example under the [tests](tests) folder.
 ## Pipeline checks
 
 To run the same checks that run during the GitHub Action build, you can use
-this command, from the `python` folder:
+this command, from the [python](../python) folder:
 
     poetry run pre-commit run -c .conf/.pre-commit-config.yaml -a
 

python/README.md

@@ -29,7 +29,7 @@ AZURE_OPENAI_API_KEY=""
 import semantic_kernel as sk
 from semantic_kernel.ai.open_ai import OpenAITextCompletion, AzureTextCompletion
 
-kernel = sk.create_kernel()
+kernel = sk.Kernel()
 
 # Prepare OpenAI backend using credentials stored in the `.env` file
 api_key, org_id = sk.openai_settings_from_dot_env()

python/pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "semantic-kernel"
-version = "0.2.2.dev"
+version = "0.2.3.dev"
 description = ""
 authors = ["Microsoft <SK-Support@microsoft.com>"]
 readme = "README.md"

python/semantic_kernel/__init__.py

@@ -2,9 +2,7 @@
 
 from semantic_kernel import core_skills, memory
 from semantic_kernel.kernel import Kernel
-from semantic_kernel.kernel_builder import KernelBuilder
 from semantic_kernel.kernel_config import KernelConfig
-from semantic_kernel.memory.null_memory import NullMemory
 from semantic_kernel.orchestration.context_variables import ContextVariables
 from semantic_kernel.orchestration.sk_context import SKContext
 from semantic_kernel.orchestration.sk_function_base import SKFunctionBase
@@ -22,17 +20,10 @@
     openai_settings_from_dot_env,
 )
 
-
-def create_kernel() -> Kernel:
-    return KernelBuilder.create_kernel()
-
-
-def kernel_builder() -> KernelBuilder:
-    return KernelBuilder(KernelConfig(), NullMemory(), NullLogger())
-
-
 __all__ = [
-    "create_kernel",
+    "Kernel",
+    "KernelConfig",
+    "NullLogger",
     "openai_settings_from_dot_env",
     "azure_openai_settings_from_dot_env",
     "PromptTemplateConfig",

python/semantic_kernel/kernel.py

@@ -13,6 +13,8 @@
 from semantic_kernel.kernel_config import KernelConfig
 from semantic_kernel.kernel_exception import KernelException
 from semantic_kernel.kernel_extensions import KernelExtensions
+from semantic_kernel.memory.memory_store_base import MemoryStoreBase
+from semantic_kernel.memory.null_memory import NullMemory
 from semantic_kernel.memory.semantic_text_memory_base import SemanticTextMemoryBase
 from semantic_kernel.orchestration.context_variables import ContextVariables
 from semantic_kernel.orchestration.sk_context import SKContext
@@ -26,9 +28,11 @@
 )
 from semantic_kernel.skill_definition.skill_collection import SkillCollection
 from semantic_kernel.skill_definition.skill_collection_base import SkillCollectionBase
+from semantic_kernel.template_engine.prompt_template_engine import PromptTemplateEngine
 from semantic_kernel.template_engine.protocols.prompt_templating_engine import (
     PromptTemplatingEngine,
 )
+from semantic_kernel.utils.null_logger import NullLogger
 from semantic_kernel.utils.validation import validate_function_name, validate_skill_name
 
 
@@ -41,17 +45,23 @@ class Kernel(KernelBase, KernelExtensions):
 
     def __init__(
         self,
-        skill_collection: SkillCollectionBase,
-        prompt_template_engine: PromptTemplatingEngine,
-        memory: SemanticTextMemoryBase,
-        config: KernelConfig,
-        log: Logger,
+        skill_collection: Optional[SkillCollectionBase] = None,
+        prompt_template_engine: Optional[PromptTemplatingEngine] = None,
+        memory: Optional[SemanticTextMemoryBase] = None,
+        config: Optional[KernelConfig] = None,
+        log: Optional[Logger] = None,
     ) -> None:
-        self._log = log
-        self._config = config
-        self._skill_collection = skill_collection
-        self._prompt_template_engine = prompt_template_engine
-        self._memory = memory
+        self._log = log if log else NullLogger()
+        self._config = config if config else KernelConfig()
+        self._skill_collection = (
+            skill_collection if skill_collection else SkillCollection(self._log)
+        )
+        self._prompt_template_engine = (
+            prompt_template_engine
+            if prompt_template_engine
+            else PromptTemplateEngine(self._log)
+        )
+        self._memory = memory if memory else NullMemory()
 
     def kernel(self) -> KernelBase:
         return self
@@ -158,6 +168,9 @@ def func(self, skill_name: str, function_name: str) -> SKFunctionBase:
     def register_memory(self, memory: SemanticTextMemoryBase) -> None:
         self._memory = memory
 
+    def register_memory_store(self, memory_store: MemoryStoreBase) -> None:
+        self.use_memory(memory_store)
+
     def create_new_context(self) -> SKContext:
         return SKContext(
             ContextVariables(),

python/tests/end-to-end/basics.py

@@ -5,7 +5,7 @@
 import semantic_kernel as sk
 import semantic_kernel.ai.open_ai as sk_oai
 
-kernel = sk.create_kernel()
+kernel = sk.Kernel()
 
 # Load credentials from .env file
 api_key, org_id = sk.openai_settings_from_dot_env()

python/tests/end-to-end/chat.py

@@ -15,7 +15,7 @@
 ChatBot:>
 """
 
-kernel = sk.create_kernel()
+kernel = sk.Kernel()
 
 api_key, org_id = sk.openai_settings_from_dot_env()
 kernel.config.add_text_backend(

python/tests/end-to-end/chat_gpt_api.py

@@ -14,7 +14,7 @@
 flowery prose.
 """
 
-kernel = sk.create_kernel()
+kernel = sk.Kernel()
 
 api_key, org_id = sk.openai_settings_from_dot_env()
 kernel.config.add_chat_backend(

python/tests/end-to-end/memory.py

@@ -7,33 +7,6 @@
 import semantic_kernel.ai.open_ai as sk_oai
 
 
-def build_kernel() -> sk.Kernel:
-    # Setup kernel with OpenAI completion and embedding backends
-    api_key, org_id = sk.openai_settings_from_dot_env()
-
-    kernel = (
-        sk.kernel_builder()
-        .configure(
-            lambda c: c.add_text_backend(
-                "davinci-003",
-                sk_oai.OpenAITextCompletion("text-davinci-003", api_key, org_id),
-            )
-        )
-        .configure(
-            lambda c: c.add_embedding_backend(
-                "ada-002",
-                sk_oai.OpenAITextEmbedding("text-embedding-ada-002", api_key, org_id),
-            )
-        )
-        .with_memory_storage(sk.memory.VolatileMemoryStore())
-        .build()
-    )
-
-    kernel.import_skill(sk.core_skills.TextMemorySkill())
-
-    return kernel
-
-
 async def populate_memory(kernel: sk.Kernel) -> None:
     # Add some documents to the semantic memory
     await kernel.memory.save_information_async(
@@ -132,7 +105,18 @@ async def chat(
 
 
 async def main() -> None:
-    kernel = build_kernel()
+    kernel = sk.Kernel()
+
+    api_key, org_id = sk.openai_settings_from_dot_env()
+    kernel.config.add_text_backend(
+        "dv", sk_oai.OpenAITextCompletion("text-davinci-003", api_key, org_id)
+    )
+    kernel.config.add_embedding_backend(
+        "ada", sk_oai.OpenAITextEmbedding("text-embedding-ada-002", api_key, org_id)
+    )
+
+    kernel.register_memory_store(memory_store=sk.memory.VolatileMemoryStore())
+    kernel.import_skill(sk.core_skills.TextMemorySkill())
 
     print("Populating memory...")
     await populate_memory(kernel)

python/tests/end-to-end/skills_from_dir.py

@@ -6,7 +6,7 @@
 import semantic_kernel as sk
 import semantic_kernel.ai.open_ai as sk_oai
 
-kernel = sk.create_kernel()
+kernel = sk.Kernel()
 
 useAzureOpenAI = False
 model = "text-davinci-002"

python/tests/integration/template_engine/test_prompt_template_e2e.py

@@ -5,7 +5,7 @@
 
 from pytest import mark, raises
 
-import semantic_kernel as sk
+from semantic_kernel import Kernel
 from semantic_kernel.skill_definition import sk_function
 from semantic_kernel.template_engine.prompt_template_engine import PromptTemplateEngine
 
@@ -54,7 +54,7 @@ async def test_it_supports_variables_async(self):
         winner = "SK"
         template = "And the winner\n of {{$input}} \nis: {{  $winner }}!"
 
-        kernel = sk.create_kernel()
+        kernel = Kernel()
         context = kernel.create_new_context()
         context["input"] = input
         context["winner"] = winner
@@ -74,7 +74,7 @@ async def test_it_supports_values_async(self):
         template = "And the winner\n of {{'template\ntests'}} \nis: {{  \"SK\" }}!"
         expected = "And the winner\n of template\ntests \nis: SK!"
 
-        kernel = sk.create_kernel()
+        kernel = Kernel()
         context = kernel.create_new_context()
 
         # Act
@@ -87,7 +87,7 @@ async def test_it_supports_values_async(self):
     async def test_it_allows_to_pass_variables_to_functions_async(self):
         # Arrange
         template = "== {{my.check123 $call}} =="
-        kernel = sk.create_kernel()
+        kernel = Kernel()
         kernel.import_skill(MySkill(), "my")
         context = kernel.create_new_context()
         context["call"] = "123"
@@ -102,7 +102,7 @@ async def test_it_allows_to_pass_variables_to_functions_async(self):
     async def test_it_allows_to_pass_values_to_functions_async(self):
         # Arrange
         template = "== {{my.check123 '234'}} =="
-        kernel = sk.create_kernel()
+        kernel = Kernel()
         kernel.import_skill(MySkill(), "my")
         context = kernel.create_new_context()
 
@@ -116,7 +116,7 @@ async def test_it_allows_to_pass_values_to_functions_async(self):
     async def test_it_allows_to_pass_escaped_values1_to_functions_async(self):
         # Arrange
         template = "== {{my.check123 'a\\'b'}} =="
-        kernel = sk.create_kernel()
+        kernel = Kernel()
         kernel.import_skill(MySkill(), "my")
         context = kernel.create_new_context()
 
@@ -130,7 +130,7 @@ async def test_it_allows_to_pass_escaped_values1_to_functions_async(self):
     async def test_it_allows_to_pass_escaped_values2_to_functions_async(self):
         # Arrange
         template = '== {{my.check123 "a\\"b"}} =='
-        kernel = sk.create_kernel()
+        kernel = Kernel()
         kernel.import_skill(MySkill(), "my")
         context = kernel.create_new_context()
 
@@ -148,7 +148,7 @@ async def test_it_handle_edge_cases_async(
         self, template: str, expected_result: str
     ):
         # Arrange
-        kernel = sk.create_kernel()
+        kernel = Kernel()
         kernel.import_skill(MySkill())
         context = kernel.create_new_context()
 

python/tests/unit/core_skills/test_file_io_skill.py

@@ -3,7 +3,7 @@
 
 import pytest
 
-import semantic_kernel as sk
+from semantic_kernel import Kernel
 from semantic_kernel.core_skills.file_io_skill import FileIOSkill
 from semantic_kernel.orchestration.context_variables import ContextVariables
 from semantic_kernel.orchestration.sk_context import SKContext
@@ -15,7 +15,7 @@ def test_can_be_instantiated():
 
 
 def test_can_be_imported():
-    kernel = sk.create_kernel()
+    kernel = Kernel()
     assert kernel.import_skill(FileIOSkill(), "file")
     assert kernel.skills.has_native_function("file", "readAsync")