Python: Add step03 getting started with processes samples. (#9427)

### Motivation and Context

Add step03 getting started with processes samples to show how to create
kernel processes related to food preparation and food ordering tasks.

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### Description

Add step03 getting started with processes samples.
- Make `emit_event` async
- Simplify how one can create an event to emit by allowing the
process_event to be a string, along with kwargs:

```
await context.emit_event(process_event=CommonEvents.StartBRequested.value, data="Get Going B")
``` 

<!-- Describe your changes, the overall approach, the underlying design.
These notes will help understanding how your code works. Thanks! -->

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [X] The code builds clean without any errors or warnings
- [X] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [X] All unit tests pass, and I have added new tests where possible
- [X] I didn't break anyone 😄

python/samples/concepts/processes/cycles_with_fan_in.py

@@ -42,8 +42,8 @@ class KickOffStep(KernelProcessStep):
 
     @kernel_function(name=KICK_OFF_FUNCTION)
     async def print_welcome_message(self, context: KernelProcessStepContext):
-        context.emit_event(KernelProcessEvent(id=CommonEvents.StartARequested.value, data="Get Going A"))
-        context.emit_event(KernelProcessEvent(id=CommonEvents.StartBRequested.value, data="Get Going B"))
+        await context.emit_event(process_event=CommonEvents.StartARequested.value, data="Get Going A")
+        await context.emit_event(process_event=CommonEvents.StartBRequested.value, data="Get Going B")
 
 
 # Define a sample `AStep` step that will emit an event after 1 second.
@@ -52,7 +52,7 @@ class AStep(KernelProcessStep):
     @kernel_function()
     async def do_it(self, context: KernelProcessStepContext):
         await asyncio.sleep(1)
-        context.emit_event(KernelProcessEvent(id=CommonEvents.AStepDone.value, data="I did A"))
+        await context.emit_event(process_event=CommonEvents.AStepDone.value, data="I did A")
 
 
 # Define a sample `BStep` step that will emit an event after 2 seconds.
@@ -61,7 +61,7 @@ class BStep(KernelProcessStep):
     @kernel_function()
     async def do_it(self, context: KernelProcessStepContext):
         await asyncio.sleep(2)
-        context.emit_event(KernelProcessEvent(id=CommonEvents.BStepDone.value, data="I did B"))
+        await context.emit_event(process_event=CommonEvents.BStepDone.value, data="I did B")
 
 
 # Define a sample `CStepState` that will keep track of the current cycle.
@@ -84,9 +84,9 @@ async def do_it(self, context: KernelProcessStepContext, astepdata: str, bstepda
         print(f"CStep Current Cycle: {self.state.current_cycle}")
         if self.state.current_cycle == 3:
             print("CStep Exit Requested")
-            context.emit_event(process_event=KernelProcessEvent(id=CommonEvents.ExitRequested.value))
+            await context.emit_event(process_event=CommonEvents.ExitRequested.value)
             return
-        context.emit_event(process_event=KernelProcessEvent(id=CommonEvents.CStepDone.value))
+        await context.emit_event(process_event=CommonEvents.CStepDone.value)
 
 
 kernel = Kernel()

python/samples/concepts/processes/nested_process.py

@@ -15,7 +15,6 @@
 from semantic_kernel.processes.kernel_process.kernel_process_step import KernelProcessStep
 from semantic_kernel.processes.kernel_process.kernel_process_step_context import KernelProcessStepContext
 from semantic_kernel.processes.kernel_process.kernel_process_step_state import KernelProcessStepState
-from semantic_kernel.processes.local_runtime.local_event import KernelProcessEvent
 from semantic_kernel.processes.local_runtime.local_kernel_process import start
 from semantic_kernel.processes.process_builder import ProcessBuilder
 from semantic_kernel.processes.process_types import TState
@@ -58,17 +57,15 @@ async def repeat(self, message: str, context: KernelProcessStepContext, count: i
         self.state.last_message = output
         print(f"[REPEAT] {output}")
 
-        context.emit_event(
-            process_event=KernelProcessEvent(
-                id=ProcessEvents.OutputReadyPublic.value, data=output, visibility=KernelProcessEventVisibility.Public
-            )
+        await context.emit_event(
+            process_event=ProcessEvents.OutputReadyPublic.value,
+            data=output,
+            visibility=KernelProcessEventVisibility.Public,
         )
-        context.emit_event(
-            process_event=KernelProcessEvent(
-                id=ProcessEvents.OutputReadyInternal.value,
-                data=output,
-                visibility=KernelProcessEventVisibility.Internal,
-            )
+        await context.emit_event(
+            process_event=ProcessEvents.OutputReadyInternal.value,
+            data=output,
+            visibility=KernelProcessEventVisibility.Internal,
         )
 
 

python/samples/getting_started_with_processes/README.md

@@ -20,7 +20,9 @@ The getting started with agents examples include:
 
 Example|Description
 ---|---
-[step01_processes](../getting_started_with_processes/step01_processes.py)|How to create a simple process with a loop and a conditional exit
+[step01_processes](../getting_started_with_processes/step01/step01_processes.py)|How to create a simple process with a loop and a conditional exit|
+[step03a_food_preparation](../getting_started_with_processes/step03/step03a_food_preparation.py)|Showcasing reuse of steps, creation of processes, spawning of multiple events, use of stateful steps with food preparation samples.
+[step03b_food_ordering](../getting_started_with_processes/step03/step03b_food_ordering.py)|Showcasing use of subprocesses as steps, spawning of multiple events conditionally reusing the food preparation samples. 
 
 ### step01_processes
 
@@ -32,6 +34,187 @@ flowchart LR
     AssistantResponse--> UserInput
 ```
 
+### step03a_food_preparation
+
+This tutorial contains a set of food recipes associated with the Food Preparation Processes of a restaurant.
+
+The following recipes for preparation of Order Items are defined as SK Processes:
+
+#### Product Preparation Processes
+
+##### Stateless Product Preparation Processes
+
+###### Potato Fries Preparation Process
+
+``` mermaid
+flowchart LR
+    PreparePotatoFriesEvent([Prepare Potato <br/> Fries Event])
+    PotatoFriesReadyEvent([Potato Fries <br/> Ready Event])
+
+    GatherIngredientsStep[Gather Ingredients <br/> Step]
+    CutStep[Cut Food <br/> Step]
+    FryStep[Fry Food <br/> Step]
+
+    PreparePotatoFriesEvent --> GatherIngredientsStep -->| Slice Potatoes <br/> _Ingredients Gathered_ | CutStep --> |**Potato Sliced Ready** <br/> _Food Sliced Ready_ | FryStep --> |_Fried Food Ready_|PotatoFriesReadyEvent
+    FryStep -->|Fried Potato Ruined <br/> _Fried Food Ruined_| GatherIngredientsStep
+```
+
+###### Fried Fish Preparation Process
+
+``` mermaid
+flowchart LR
+    PrepareFriedFishEvent([Prepare Fried <br/> Fish Event])
+    FriedFishReadyEvent([Fried Fish <br/> Ready Event])
+
+    GatherIngredientsStep[Gather Ingredients <br/> Step]
+    CutStep[Cut Food <br/> Step]
+    FryStep[Fry Food <br/> Step]
+
+    PrepareFriedFishEvent --> GatherIngredientsStep -->| Chop Fish <br/> _Ingredients Gathered_ | CutStep --> |**Fish Chopped Ready** <br/> _Food Chopped Ready_| FryStep --> |_Fried Food Ready_ | FriedFishReadyEvent
+    FryStep -->|**Fried Fish Ruined** <br/> _Fried Food Ruined_| GatherIngredientsStep
+```
+
+###### Fish Sandwich Preparation Process
+
+``` mermaid
+flowchart LR
+    PrepareFishSandwichEvent([Prepare Fish <br/> Sandwich Event])
+    FishSandwichReadyEvent([Fish Sandwich <br/> Ready Event])
+
+    FriedFishStep[[Fried Fish <br/> Process Step]]
+    AddBunsStep[Add Buns <br/> Step]
+    AddSpecialSauceStep[Add Special <br/> Sauce Step]
+
+    PrepareFishSandwichEvent -->|Prepare Fried Fish| FriedFishStep -->|Fried Fish Ready| AddBunsStep --> |Buns Added  | AddSpecialSauceStep --> |Special Sauce Added | FishSandwichReadyEvent
+```
+
+###### Fish And Chips Preparation Process
+
+``` mermaid
+flowchart LR
+    PrepareFishAndChipsEvent([Prepare <br/> Fish And Chips <br/> Event])
+    FishAndChipsReadyEvent([Fish And Chips <br/> Ready Event])
+
+    FriedFishStep[[Fried Fish <br/> Process Step]]
+    PotatoFriesStep[[Potato Fries  <br/> Process Step]]
+    AddCondiments[Add Condiments <br/> Step ]
+
+    PrepareFishAndChipsEvent -->|Prepare Fried Fish| FriedFishStep --> |Fried Fish Ready| AddCondiments
+    PrepareFishAndChipsEvent -->|Prepare Potato Fries| PotatoFriesStep -->|Potato Fries Ready| AddCondiments
+    AddCondiments -->|Condiments Added| FishAndChipsReadyEvent
+```
+
+##### Stateful Product Preparation Processes
+
+The processes in this subsection contain the following modifications/additions to previously used food preparation processes:
+
+- The `Gather Ingredients Step` is now stateful and has a predefined number of initial ingredients that are used as orders are prepared. When there are no ingredients left, it emits the `Out of Stock Event`.
+- The `Cut Food Step` is now a stateful component which has a `Knife Sharpness State` that tracks the Knife Sharpness.
+- As the `Slice Food` and `Chop Food` Functions get invoked, the Knife Sharpness deteriorates.
+- The `Cut Food Step` has an additional input function `Sharpen Knife Function`.
+- The new `Sharpen Knife Function` sharpens the knife and increases the Knife Sharpness - Knife Sharpness State.
+- From time to time, the `Cut Food Step`'s functions `SliceFood` and `ChopFood` will fail and emit a `Knife Needs Sharpening Event` that then triggers the `Sharpen Knife Function`.
+
+
+###### Potato Fries Preparation With Knife Sharpening and Ingredient Stock Process
+
+The following processes is a modification on the process [Potato Fries Preparation](#potato-fries-preparation-process) 
+with the the stateful steps mentioned previously.
+
+``` mermaid
+flowchart LR
+    PreparePotatoFriesEvent([Prepare Potato <br/> Fries Event])
+    PotatoFriesReadyEvent([Potato Fries <br/> Ready Event])
+    OutOfStock([Ingredients <br/> Out of Stock <br/> Event])
+
+    FryStep[Fry Food <br/> Step]
+
+    subgraph GatherIngredientsStep[Gather Ingredients Step]
+        GatherIngredientsFunction[Gather Potato <br/> Function]
+        IngredientsState[(Ingredients <br/> Stock <br/> State)]
+    end
+    subgraph CutStep ["Cut Food Step"]
+        direction LR
+        SliceFoodFunction[Slice Food <br/> Function]
+        SharpenKnifeFunction[Sharpen Knife <br/> Function]
+        CutState[(Knife <br/> Sharpness <br/> State)]
+    end
+    
+    CutStep --> |**Potato Sliced Ready** <br/> _Food Sliced Ready_ | FryStep --> |_Fried Food Ready_|PotatoFriesReadyEvent
+    FryStep -->|Fried Potato Ruined <br/> _Fried Food Ruined_| GatherIngredientsStep
+    GatherIngredientsStep --> OutOfStock
+    
+    SliceFoodFunction --> |Knife Needs Sharpening| SharpenKnifeFunction
+    SharpenKnifeFunction --> |Knife Sharpened| SliceFoodFunction
+
+    GatherIngredientsStep -->| Slice Potatoes <br/> _Ingredients Gathered_ | CutStep
+    PreparePotatoFriesEvent --> GatherIngredientsStep 
+```
+
+###### Fried Fish Preparation With Knife Sharpening and Ingredient Stock Process
+
+The following process is a modification on the process [Fried Fish Preparation](#fried-fish-preparation-process) 
+with the the stateful steps mentioned previously.
+
+``` mermaid
+flowchart LR
+    PrepareFriedFishEvent([Prepare Fried <br/> Fish Event])
+    FriedFishReadyEvent([Fried Fish <br/> Ready Event])
+    OutOfStock([Ingredients <br/> Out of Stock <br/> Event])
+
+    FryStep[Fry Food <br/> Step]
+
+    subgraph GatherIngredientsStep[Gather Ingredients Step]
+        GatherIngredientsFunction[Gather Fish <br/> Function]
+        IngredientsState[(Ingredients <br/> Stock <br/> State)]
+    end
+    subgraph CutStep ["Cut Food Step"]
+        direction LR
+        ChopFoodFunction[Chop Food <br/> Function]
+        SharpenKnifeFunction[Sharpen Knife <br/> Function]
+        CutState[(Knife <br/> Sharpness <br/> State)]
+    end
+    
+    CutStep --> |**Fish Chopped Ready** <br/> _Food Chopped Ready_| FryStep --> |_Fried Food Ready_|FriedFishReadyEvent
+    FryStep -->|**Fried Fish Ruined** <br/> _Fried Food Ruined_| GatherIngredientsStep
+    GatherIngredientsStep --> OutOfStock
+    
+    ChopFoodFunction --> |Knife Needs Sharpening| SharpenKnifeFunction
+    SharpenKnifeFunction --> |Knife Sharpened| ChopFoodFunction
+
+    GatherIngredientsStep -->| Chop Fish <br/> _Ingredients Gathered_ | CutStep
+    PrepareFriedFishEvent --> GatherIngredientsStep 
+```
+
+### step03b_food_ordering
+
+#### Single Order Preparation Process
+
+Now with the existing product preparation processes, they can be used to create an even more complex process that can decide what product order to dispatch.
+
+```mermaid
+graph TD
+    PrepareSingleOrderEvent([Prepare Single Order <br/> Event])
+    SingleOrderReadyEvent([Single Order <br/> Ready Event])
+    OrderPackedEvent([Order Packed <br/> Event])
+
+    DispatchOrderStep{{Dispatch <br/> Order Step}}
+    FriedFishStep[[Fried Fish  <br/> Process Step]]
+    PotatoFriesStep[[Potato Fries <br/> Process Step]]
+    FishSandwichStep[[Fish Sandwich <br/> Process Step]]
+    FishAndChipsStep[[Fish & Chips <br/> Process Step]]
+
+    PackFoodStep[Pack Food <br/> Step]
+
+    PrepareSingleOrderEvent -->|Order Received| DispatchOrderStep
+    DispatchOrderStep -->|Prepare Fried Fish| FriedFishStep -->|Fried Fish Ready| SingleOrderReadyEvent
+    DispatchOrderStep -->|Prepare Potato Fries| PotatoFriesStep -->|Potato Fries Ready| SingleOrderReadyEvent
+    DispatchOrderStep -->|Prepare Fish Sandwich| FishSandwichStep -->|Fish Sandwich Ready| SingleOrderReadyEvent
+    DispatchOrderStep -->|Prepare Fish & Chips| FishAndChipsStep -->|Fish & Chips Ready| SingleOrderReadyEvent
+
+    SingleOrderReadyEvent-->PackFoodStep --> OrderPackedEvent
+```
+
 ## Configuring the Kernel
 
 Similar to the Semantic Kernel Python concept samples, it is necessary to configure the secrets

python/samples/getting_started_with_processes/step01_processes.py → python/samples/getting_started_with_processes/step01/step01_processes.py

@@ -70,13 +70,13 @@ async def get_user_input(self, context: KernelProcessStepContext):
         print(f"USER: {user_message}")
 
         if "exit" in user_message:
-            context.emit_event(KernelProcessEvent(id=ChatBotEvents.Exit.value, data=None))
+            await context.emit_event(process_event=ChatBotEvents.Exit.value, data=None)
             return
 
         self.state.current_input_index += 1
 
         # Emit the user input event
-        context.emit_event({"id": CommonEvents.UserInputReceived.value, "data": user_message})
+        await context.emit_event(process_event=CommonEvents.UserInputReceived.value, data=user_message)
 
 
 class ChatUserInputStep(ScriptedUserInputStep):
@@ -140,9 +140,7 @@ async def get_chat_response(self, context: "KernelProcessStepContext", user_mess
         self.state.chat_messages.append(answer)
 
         # Emit an event: assistantResponse
-        context.emit_event(
-            process_event=KernelProcessEvent(id=ChatBotEvents.AssistantResponseGenerated.value, data=answer)
-        )
+        await context.emit_event(process_event=ChatBotEvents.AssistantResponseGenerated.value, data=answer)
 
 
 kernel = Kernel()

python/samples/getting_started_with_processes/step03/models/__init__.py

@@ -0,0 +1,6 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from samples.getting_started_with_processes.step03.models.food_ingredients import FoodIngredients
+from samples.getting_started_with_processes.step03.models.food_order_item import FoodItem
+
+__all__ = ["FoodIngredients", "FoodItem"]

python/samples/getting_started_with_processes/step03/models/food_ingredients.py

@@ -0,0 +1,15 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from enum import Enum
+
+
+class FoodIngredients(str, Enum):
+    POTATOES = "Potatoes"
+    FISH = "Fish"
+    BUNS = "Buns"
+    SAUCE = "Sauce"
+    CONDIMENTS = "Condiments"
+    NONE = "None"
+
+    def to_friendly_string(self) -> str:
+        return self.value

python/samples/getting_started_with_processes/step03/models/food_order_item.py

@@ -0,0 +1,13 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from enum import Enum
+
+
+class FoodItem(str, Enum):
+    POTATO_FRIES = "Potato Fries"
+    FRIED_FISH = "Fried Fish"
+    FISH_SANDWICH = "Fish Sandwich"
+    FISH_AND_CHIPS = "Fish & Chips"
+
+    def to_friendly_string(self) -> str:
+        return self.value

python/samples/getting_started_with_processes/step03/processes/__init__.py

@@ -0,0 +1,7 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from samples.getting_started_with_processes.step03.processes.fish_and_chips_process import FishAndChipsProcess
+from samples.getting_started_with_processes.step03.processes.fish_sandwich_process import FishSandwichProcess
+from samples.getting_started_with_processes.step03.processes.fried_fish_process import FriedFishProcess
+
+__all__ = ["FishAndChipsProcess", "FriedFishProcess", "FishSandwichProcess"]