Introduction

This project provides a Python data model for creating and manipulating UML diagrams. It's the foundational data model for the UML Shapes module.

Installation

It is recommended to use a virtual environment for installing Python packages.

# Create and activate a virtual environment
python -m venv venv
source venv/bin/activate

# Install the package
pip install umlmodel

Usage

Programmatic Usage

The umlmodel library allows you to create UML elements like classes, interfaces, and use cases programmatically. Here are some examples:

Creating a Class

To create a simple class, instantiate the Class object:

from umlmodel.Class import Class

modelClass: Class = Class(name='MyClass')

print(modelClass.name)

Adding Fields to a Class

You can add fields (attributes) to a class. Fields have a name, type, visibility, and an optional default value.

from umlmodel.Class import Class
from umlmodel.Field import Field
from umlmodel.FieldType import FieldType
from umlmodel.enumerations.Visibility import Visibility

# Create a class
modelClass: Class = Class(name='MyClass')

# Create fields
field1: Field = Field(name='my_string',
               type=FieldType('str'),
               visibility=Visibility.PUBLIC,
               defaultValue='"hello"')
field2:Field = Field(name='_my_private_int',
               type=FieldType('int'),
               visibility=Visibility.PRIVATE)

# Add fields to the class
modelClass.fields.append(field1)
modelClass.fields.append(field2)

# The string representation of a field is useful
print(field1)
print(field2)

Adding Methods to a Class

Methods can be added to a class, including parameters and return types.

from umlmodel.Class import Class
from umlmodel.Method import Method
from umlmodel.Parameter import Parameter
from umlmodel.ParameterType import ParameterType
from umlmodel.ReturnType import ReturnType
from umlmodel.enumerations.Visibility import Visibility

# Create a class
modelClass: Class = Class(name='MyClass')

# Create a method
method: Method = Method(name='my_method', visibility=Visibility.PUBLIC)

# Add a parameter
parameter: Paraeter = Parameter(name='value', type=ParameterType('int'), defaultValue='0')
method.addParameter(parameter)

# Set a return type
method.returnType = ReturnType('bool')

# Add the method to the class
modelClass.methods.append(method)

# Print the method signature
print(method.methodWithParameters())

---

Written by Humberto A. Sanchez II <mailto@Humberto.A.Sanchez.II@gmail.com>, (C) 2025

Note

For all kind of problems, requests, enhancements, bug reports, etc., please drop me an e-mail.

---

I am concerned about GitHub's Copilot project

I urge you to read about the Give up GitHub campaign fromthe Software Freedom Conservancy.

While I do not advocate for all the issues listed there I do not like that a company like Microsoft may profit from open source projects.

I continue to use GitHub because it offers the services I need for free. But, I continue to monitor their terms of service.

Any use of this project's code by GitHub Copilot, past or present, is done without my permission. I do not consent to GitHub's use of this project's code in Copilot.