mergram 0.3.0

Programmatically construct Mermaid diagrams and charts in Python

MerGram

Programmatically generate Mermaid diagrams and charts using Python.

MerGram currently supports constructing Mermaid flowcharts, with plans to expand support for additional diagram and chart types in future releases.

Features

• Build Mermaid flowcharts using Python classes
• Support for nodes, links, and subgraphs, and style assignments
• Export diagrams to Mermaid .mmd or .mermaid files
• Optional integration with networkx for graph conversion

What's New in

v0.3.0

• Style class that can be used to add style ... lines to flowcharts
• Fixes to style-related outputs for nodes

v0.2.0

• Flowchart.to_markdown function to get a string representation of the flowchart embedded in a Markdown Mermaid code block.
• Flowchart.to_html function to get a string representation of the flowchart embedded in HTML.

Installation

pip install mergram

To enable networkx integration:

pip install mergram[networkx]

Usage

Basic Flowchart

from mergram.flowchart import Flowchart, Node, Link

fc = Flowchart("Example Flowchart")
a = Node("A", label="Start")
b = Node("B", label="End", shape='circle')
fc += a
fc += b
fc += Link(a, b, text="to end")

print(fc)

Generates the following mermaid diagram code:

---
title: Example Flowchart
---
flowchart TB
    A@{ shape: rect, label: Start }
    B@{ shape: circle, label: End }
    A-->|to end|B
    style A fill:#fff, stroke:#000, stroke-width:2px, color:#000
    style B fill:#fff, stroke:#000, stroke-width:2px, color:#000

That looks like:

---
 title: Example Flowchart
---
flowchart TB
    A@{ shape: rect, label: Start }
    B@{ shape: circle, label: End }
    A-->|to end|B
    style A fill:#fff, stroke:#000, stroke-width:2px, color:#000
    style B fill:#fff, stroke:#000, stroke-width:2px, color:#000

From NetworkX

import networkx as nx
from mergram.flowchart import Flowchart

G = nx.DiGraph()
G.add_edge("A", "B", label="to B")
G.add_edge("B", "A", label="to A")
fc = Flowchart("From NetworkX", orientation='LR')
fc.from_networkx(G)
print(fc)

---
title: From NetworkX
---
flowchart LR
    B@{ shape: rect, label: B }
    A@{ shape: rect, label: A }
    A-->|to B|B
    B-->|to A|A
    style A fill:#fff, stroke:#000, stroke-width:2px, color:#000
    style B fill:#fff, stroke:#000, stroke-width:2px, color:#000

---
 title: From NetworkX
---
flowchart LR
    B@{ shape: rect, label: B }
    A@{ shape: rect, label: A }
    A-->|to B|B
    B-->|to A|A
    style A fill:#fff, stroke:#000, stroke-width:2px, color:#000
    style B fill:#fff, stroke:#000, stroke-width:2px, color:#000

Export to File

fc.write("diagram.mmd")

Optional Dependencies

• networkx: For converting existing graphs to Mermaid flowcharts.

License

MIT License

Contributing

Contributions are welcome! Please open issues or pull requests.