Introduction

This project provides a Python data model for creating and manipulating UML diagrams. It is 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: Parameter = 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())

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Written by Humberto A. Sanchez II (C) 2026

Note

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

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