refactor(examples) Update Flower example using scikit-learn

examples/sklearn-logreg-mnist/README.md

@@ -4,83 +4,64 @@ dataset: [MNIST]
 framework: [scikit-learn]
 ---
 
-# Flower Logistic Regression Example using scikit-learn
+# Flower Logistic Regression Example using scikit-learn and Flower (Quickstart Example)
 
-This example of Flower uses `scikit-learn`'s `LogisticRegression` model to train a federated learning system. It will help you understand how to adapt Flower for use with `scikit-learn`.
+This example of Flower uses `scikit-learn`'s [LogisticRegression](https://scikit-learn.org/stable/modules/generated/sklearn.linear_model.LogisticRegression.html) model to train a federated learning system. It will help you understand how to adapt Flower for use with `scikit-learn`.
 Running this example in itself is quite easy. This example uses [Flower Datasets](https://flower.ai/docs/datasets/) to download, partition and preprocess the MNIST dataset.
 
-## Project Setup
+## Set up the project
 
-Start by cloning the example project. We prepared a single-line command that you can copy into your shell which will checkout the example for you:
+### Clone the project
 
-```shell
-git clone --depth=1 https://github.com/adap/flower.git && mv flower/examples/sklearn-logreg-mnist . && rm -rf flower && cd sklearn-logreg-mnist
-```
-
-This will create a new directory called `sklearn-logreg-mnist` containing the following files:
+Start by cloning the example project:
 
 ```shell
--- pyproject.toml
--- requirements.txt
--- client.py
--- server.py
--- utils.py
--- README.md
+git clone --depth=1 https://github.com/adap/flower.git _tmp \
+		&& mv _tmp/examples/sklearn-logreg-mnist . \
+		&& rm -rf _tmp && cd sklearn-logreg-mnist
 ```
 
-### Installing Dependencies
-
-Project dependencies (such as `scikit-learn` and `flwr`) are defined in `pyproject.toml` and `requirements.txt`. We recommend [Poetry](https://python-poetry.org/docs/) to install those dependencies and manage your virtual environment ([Poetry installation](https://python-poetry.org/docs/#installation)) or [pip](https://pip.pypa.io/en/latest/development/), but feel free to use a different way of installing dependencies and managing virtual environments if you have other preferences.
-
-#### Poetry
+This will create a new directory called `sklearn-logreg-mnist` with the following structure:
 
 ```shell
-poetry install
-poetry shell
+sklearn-logreg-mnist
+├── README.md
+├── pyproject.toml      # Project metadata like dependencies and configs
+└── sklearn_example
+    ├── __init__.py
+    ├── client_app.py   # Defines your ClientApp
+    ├── server_app.py   # Defines your ServerApp
+    └── task.py         # Defines your model, training and data loading
 ```
 
-Poetry will install all your dependencies in a newly created virtual environment. To verify that everything works correctly you can run the following command:
+### Install dependencies and project
 
-```shell
-poetry run python3 -c "import flwr"
-```
-
-If you don't see any errors you're good to go!
-
-#### pip
+Install the dependencies defined in `pyproject.toml` as well as the `sklearn_example` package.
 
-Write the command below in your terminal to install the dependencies according to the configuration file requirements.txt.
-
-```shell
-pip install -r requirements.txt
+```bash
+pip install -e .
 ```
 
-## Run Federated Learning with scikit-learn and Flower
-
-Afterwards you are ready to start the Flower server as well as the clients. You can simply start the server in a terminal as follows:
-
-```shell
-poetry run python3 server.py
-```
+## Run the project
 
-Now you are ready to start the Flower clients which will participate in the learning. To do so simply open two or more terminals and run the following command in each:
+You can run your Flower project in both _simulation_ and _deployment_ mode without making changes to the code. If you are starting with Flower, we recommend you using the _simulation_ mode as it requires fewer components to be launched manually. By default, `flwr run` will make use of the Simulation Engine.
 
-Start client 1 in the first terminal:
+### Run with the Simulation Engine
 
-```shell
-python3 client.py --partition-id 0 # or any integer in {0-9}
+```bash
+flwr run .
 ```
 
-Start client 2 in the second terminal:
+You can also override some of the settings for your `ClientApp` and `ServerApp` defined in `pyproject.toml`. For example:
 
-```shell
-python3 client.py --partition-id 1 # or any integer in {0-9}
+```bash
+flwr run . --run-config num-server-rounds=5,fraction-fit=0.25
 ```
 
-Alternatively, you can run all of it in one shell as follows:
+> \[!TIP\]
+> For a more detailed walk-through check our [quickstart PyTorch tutorial](https://flower.ai/docs/framework/tutorial-quickstart-scikitlearn.html)
 
-```bash
-bash run.sh
-```
+### Run with the Deployment Engine
 
-You will see that Flower is starting a federated training.
+> \[!NOTE\]
+> An update to this example will show how to run this Flower application with the Deployment Engine and TLS certificates, or with Docker.

examples/sklearn-logreg-mnist/pyproject.toml

@@ -1,19 +1,40 @@
 [build-system]
-requires = ["poetry-core>=1.4.0"]
-build-backend = "poetry.core.masonry.api"
+requires = ["hatchling"]
+build-backend = "hatchling.build"
 
-[tool.poetry]
-name = "sklearn-mnist"
-version = "0.1.0"
+[project]
+name = "sklearnexample"
+version = "1.0.0"
+license = "Apache-2.0"
 description = "Federated learning with scikit-learn and Flower"
 authors = [
-    "The Flower Authors <hello@flower.ai>",
-    "Kaushik Amar Das <kaushik.das@iiitg.ac.in>",
+    { name = "The Flower Authors", email = "hello@flower.ai" },
+    { name = "Kaushik Amar Das", email = "kaushik.das@iiitg.ac.in" },
 ]
+dependencies = [
+    "flwr[simulation]>=1.10.0",
+    "flwr-datasets[vision]>=0.3.0",
+    "numpy<2.0.0",
+    "scikit-learn~=1.2.2",
+]
+
+[tool.hatch.build.targets.wheel]
+packages = ["."]
+
+[tool.flwr.app]
+publisher = "flwrlabs"
+
+[tool.flwr.app.components]
+serverapp = "sklearnexample.server_app:app"
+clientapp = "sklearnexample.client_app:app"
+
+[tool.flwr.app.config]
+penalty = "l2"
+num-server-rounds = 3
+fraction-fit = 0.5
+
+[tool.flwr.federations]
+default = "local-simulation"
 
-[tool.poetry.dependencies]
-python = "^3.8"
-flwr = ">=1.0,<2.0"
-# flwr = { path = "../../", develop = true }  # Development
-flwr-datasets = { extras = ["vision"], version = ">=0.0.2,<1.0.0" }
-scikit-learn = "^1.1.1"
+[tool.flwr.federations.local-simulation]
+options.num-supernodes = 10

examples/sklearn-logreg-mnist/sklearnexample/__init__.py

@@ -0,0 +1 @@
+"""sklearn_example."""

examples/sklearn-logreg-mnist/sklearnexample/client_app.py

@@ -0,0 +1,60 @@
+"""sklearnexample: A Flower / scikit-learn app."""
+
+import warnings
+
+from flwr.client import Client, ClientApp, NumPyClient
+from flwr.common import Context
+
+from sklearn.metrics import log_loss
+from sklearnexample.task import (
+    create_log_reg_and_instantiate_parameters,
+    get_model_parameters,
+    load_data,
+    set_model_params,
+)
+
+
+# Define Flower client
+class MnistClient(NumPyClient):
+    def __init__(self, model, X_train, X_test, y_train, y_test):
+        self.model = model
+        self.X_train = X_train
+        self.X_test = X_test
+        self.y_train = y_train
+        self.y_test = y_test
+
+    def fit(self, parameters, config):
+        set_model_params(self.model, parameters)
+        # Ignore convergence failure due to low local epochs
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore")
+            self.model.fit(self.X_train, self.y_train)
+        return get_model_parameters(self.model), len(self.X_train), {}
+
+    def evaluate(self, parameters, config):
+        set_model_params(self.model, parameters)
+        loss = log_loss(self.y_test, self.model.predict_proba(self.X_test))
+        accuracy = self.model.score(self.X_test, self.y_test)
+        return loss, len(self.X_test), {"accuracy": accuracy}
+
+
+def client_fn(context: Context) -> Client:
+    """Construct a Client that will be run in a ClientApp."""
+
+    # Read the node_config to fetch data partition associated to this node
+    partition_id = context.node_config["partition-id"]
+    num_partitions = context.node_config["num-partitions"]
+    X_train, X_test, y_train, y_test = load_data(partition_id, num_partitions)
+
+    # Read the run config to get settings to configure the Client
+    penalty = context.run_config["penalty"]
+
+    # Create LogisticRegression Model
+    model = create_log_reg_and_instantiate_parameters(penalty)
+
+    # Return Client instance
+    return MnistClient(model, X_train, X_test, y_train, y_test).to_client()
+
+
+# Create ClientApp
+app = ClientApp(client_fn=client_fn)