Last updated: 16 Feb 2023

👋 PyCaret Clustering Tutorial¶

PyCaret is an open-source, low-code machine learning library in Python that automates machine learning workflows. It is an end-to-end machine learning and model management tool that exponentially speeds up the experiment cycle and makes you more productive.

Compared with the other open-source machine learning libraries, PyCaret is an alternate low-code library that can be used to replace hundreds of lines of code with a few lines only. This makes experiments exponentially fast and efficient. PyCaret is essentially a Python wrapper around several machine learning libraries and frameworks, such as scikit-learn, XGBoost, LightGBM, CatBoost, spaCy, Optuna, Hyperopt, Ray, and a few more.

The design and simplicity of PyCaret are inspired by the emerging role of citizen data scientists, a term first used by Gartner. Citizen Data Scientists are power users who can perform both simple and moderately sophisticated analytical tasks that would previously have required more technical expertise.

💻 Installation¶

PyCaret is tested and supported on the following 64-bit systems:

• Python 3.7 – 3.10
• Python 3.9 for Ubuntu only
• Ubuntu 16.04 or later
• Windows 7 or later

You can install PyCaret with Python's pip package manager:

pip install pycaret

PyCaret's default installation will not install all the extra dependencies automatically. For that you will have to install the full version:

pip install pycaret[full]

or depending on your use-case you may install one of the following variant:

• pip install pycaret[analysis]
• pip install pycaret[models]
• pip install pycaret[tuner]
• pip install pycaret[mlops]
• pip install pycaret[parallel]
• pip install pycaret[test]

🚀 Quick start¶

PyCaret's Clustering Module is an unsupervised machine learning module that performs the task of grouping a set of objects in such a way that objects in the same group (also known as a cluster) are more similar to each other than to those in other groups.

It provides several pre-processing features that prepare the data for modeling through the setup function. It has over 10 ready-to-use algorithms and several plots to analyze the performance of trained models.

A typical workflow in PyCaret's unsupervised module consist of following 6 steps in this order:

Setup ➡️ Create Model ➡️ Assign Labels ➡️ Analyze Model ➡️ Prediction ➡️ Save Model¶

Setup¶

This function initializes the training environment and creates the transformation pipeline. Setup function must be called before executing any other function in PyCaret. It only has one required parameter i.e. data. All the other parameters are optional.

Once the setup has been successfully executed it shows the information grid containing experiment level information.

• Session id: A pseudo-random number distributed as a seed in all functions for later reproducibility. If no session_id is passed, a random number is automatically generated that is distributed to all functions.
  

- **Original data shape:** Shape of the original data prior to any transformations.

- **Transformed data shape:** Shape of data after transformations

- **Numeric features :** The number of features considered as numerical.

- **Categorical features :** The number of features considered as categorical.

PyCaret has two set of API's that you can work with. (1) Functional (as seen above) and (2) Object Oriented API.

With Object Oriented API instead of executing functions directly you will import a class and execute methods of class.

You can use any of the two method i.e. Functional or OOP and even switch back and forth between two set of API's. The choice of method will not impact the results and has been tested for consistency. ___

Create Model¶

This function trains and evaluates the performance of a given model. Metrics evaluated can be accessed using the get_metrics function. Custom metrics can be added or removed using the add_metric and remove_metric function. All the available models can be accessed using the models function.

Assign Model¶

This function assigns cluster labels to the training data, given a trained model.

Analyze Model¶

You can use the plot_model function to analyzes the performance of a trained model on the test set. It may require re-training the model in certain cases.

An alternate to plot_model function is evaluate_model. It can only be used in Notebook since it uses ipywidget.

Prediction¶

The predict_model function returns Cluster label as a new column in the input dataframe. This step may or may not be needed depending on the use-case. Some times clustering models are trained for analysis purpose only and the interest of user is only in assigned labels on the training dataset, that can be done using assign_model function. predict_model is only useful when you want to obtain cluster labels on unseen data (i.e. data that was not used during training the model).

Save Model¶

Finally, you can save the entire pipeline on disk for later use, using pycaret's save_model function.

👇 Detailed function-by-function overview¶

✅ Setup¶

This function initializes the training environment and creates the transformation pipeline. Setup function must be called before executing any other function in PyCaret. It only has one required parameter i.e. data. All the other parameters are optional.

To access all the variables created by the setup function such as transformed dataset, random_state, etc. you can use get_config method.

All the preprocessing configurations and experiment settings/parameters are passed into the setup function. To see all available parameters, check the docstring:

Notice that all the values are between 0 and 1 - that is because we passed normalize=True in the setup function. If you don't remember how it compares to actual data, no problem - we can also access non-transformed values using get_config and then compare. See below and notice the range of values on x-axis and compare it with histogram above.

✅ Experiment Logging¶

PyCaret integrates with many different type of experiment loggers (default = 'mlflow'). To turn on experiment tracking in PyCaret you can set log_experiment and experiment_name parameter. It will automatically track all the metrics, hyperparameters, and artifacts based on the defined logger.

By default PyCaret uses MLFlow logger that can be changed using log_experiment parameter. Following loggers are available:

- mlflow
- wandb
- comet_ml
- dagshub

Other logging related parameters that you may find useful are:

• experiment_custom_tags
• log_plots
• log_data
• log_profile

For more information check out the docstring of the setup function.

✅ Create Model¶

This function trains and evaluates the performance of a given estimator using cross-validation. The output of this function is a scoring grid with CV scores by fold. Metrics evaluated during CV can be accessed using the get_metrics function. Custom metrics can be added or removed using add_metric and remove_metric function. All the available models can be accessed using the models function.

The function above has return trained model object as an output. The scoring grid is only displayed and not returned. If you need access to the scoring grid you can use pull function to access the dataframe.

Some other parameters that you might find very useful in create_model are:

• num_clusters
• ground_truth
• fit_kwargs
• experiment_custom_tags
• engine

You can check the docstring of the function for more info.

✅ Assign Model¶

This function assigns cluster labels to the training data, given a trained model.

✅ Plot Model¶

This function analyzes the performance of a trained model.

Some other parameters that you might find very useful in plot_model are:

• feature
• label
• display_format

You can check the docstring of the function for more info.

✅ Deploy Model¶

This function deploys the entire ML pipeline on the cloud.

AWS: When deploying model on AWS S3, environment variables must be configured using the command-line interface. To configure AWS environment variables, type aws configure in terminal. The following information is required which can be generated using the Identity and Access Management (IAM) portal of your amazon console account:

• AWS Access Key ID
• AWS Secret Key Access
• Default Region Name (can be seen under Global settings on your AWS console)
• Default output format (must be left blank)

GCP: To deploy a model on Google Cloud Platform ('gcp'), the project must be created using the command-line or GCP console. Once the project is created, you must create a service account and download the service account key as a JSON file to set environment variables in your local environment. Learn more about it: https://cloud.google.com/docs/authentication/production

Azure: To deploy a model on Microsoft Azure ('azure'), environment variables for the connection string must be set in your local environment. Go to settings of storage account on Azure portal to access the connection string required. AZURE_STORAGE_CONNECTION_STRING (required as environment variable) Learn more about it: https://docs.microsoft.com/en-us/azure/storage/blobs/storage-quickstart-blobs-python?toc=%2Fpython%2Fazure%2FTOC.json

✅ Save / Load Model¶

This function saves the transformation pipeline and a trained model object into the current working directory as a pickle file for later use.

✅ Save / Load Experiment¶

This function saves all the experiment variables on disk, allowing to later resume without rerunning the setup function.