yEd Py

A simple Python library to export networks to yEd.

Is is available from PyPI.

The yEd Graph Editor supports the GraphML (GraphML Primer) file format. This is an open standard based on XML, and is supported by Python libraries such as NetworkX. However, the details of formatting (rather than network topology) are handled by yEd specific extensions to the standard, which are not supported by other libraries.

I therefore wrote this library to provide an easy interface that lets you specify how a graph should look, and generates corresponding graphML that can be opened in yEd.

Usage

The interface is similar to that of NetworkX:

import pyyed

g = pyyed.Graph()

g.add_node('foo', font_family="Zapfino")
g.add_node('foo2', shape="roundrectangle", font_style="bolditalic", underlined_text="true")

g.add_edge('foo1', 'foo2')
g.add_node('abc', font_size="72", height="100", shape_fill="#FFFFFF")

g.add_node('bar', label="Multi\nline\ntext")
g.add_node('foobar', label="""Multi
    Line
    Text!""")

g.add_edge('foo', 'foo1', label="EDGE!", width="3.0", color="#0000FF", 
               arrowhead="white_diamond", arrowfoot="standard", line_type="dotted")

print(g.get_graph())

# To write to file:
with open('test_graph.graphml', 'w') as fp:
    fp.write(g.get_graph())

# Or:
g.write_graph('example.graphml')

# Or, to pretty-print with whitespace:
g.write_graph('pretty_example.graphml', pretty_print=True)

Saving this to a file with a .graphml extension, opening in yEd, applying Tools -> Fit Node to Label and Layout -> One-click layout produces something like the following:

UML

The file examples/demo-uml.py, includes an example UML diagram:

The arrowheads used in UML class diagrams correspond to crows_foot_one_optional (association or dependency), white_delta (inheritance or implementation), white_diamond (aggregation), and diamond (composition).

The line_type is either line or dashed.

Options

Valid node shapes are: "rectangle", "rectangle3d", "roundrectangle", "diamond", "ellipse", "fatarrow", "fatarrow2", "hexagon", "octagon", "parallelogram", "parallelogram2", "star5", "star6", "star6", "star8", "trapezoid", "trapezoid2", "triangle", "trapezoid2", "triangle"

Valid line_types are: "line", "dashed", "dotted", "dashed_dotted"

Valid font_styles are: "plain", "bold", "italic", "bolditalic"

Valid arrow_types are: "none", "standard", "white_delta", "diamond", "white_diamond", "short", "plain", "concave", "concave", "convex", "circle", "transparent_circle", "dash", "skewed_dash", "t_shape", "crows_foot_one_mandatory", "crows_foot_many_mandatory", "crows_foot_many_optional", "crows_foot_many_optional", "crows_foot_one", "crows_foot_many", "crows_foot_optional"

Development

Requirements:

$ pip install pytest

Run the tests:

$ PYTHONPATH=. pytest tests