vizzpy 0.6.0

Interactive Python call tree visualizer — upload a project, explore its call graph in the browser

VizzPy

Interactive Python call tree visualizer. Upload a Python project and explore its function call graph in the browser. Here are some usecases:

• Bake the headless mode in your CI pipeline for adding auto-generated call tree in your repo (auto-documentation helping in understaanding the functionality and its implementation)
• Use in interactive mode to explore and understand the implementation of a particular functionality. This can also be helpful ahead of code reviews.

Features

• Interactive web UI — zoom, pan, drag nodes, collapse subtrees
• Two granularity levels — toggle between function-level and module-level call graph in the UI or via --level
• Cross-module resolution — follows imports across files to draw edges between modules
• Dark mode — toggle with one click
• Headless mode — render a static SVG or Mermaid flowchart from the command line (SVG requires Graphviz)
• Archive upload — drag-and-drop a .zip, .tar.gz, .egg, or .whl in the web UI; pass a folder path in headless mode

Installation

Install only what you need:

Goal	Command
Mermaid headless (CI-friendly, zero extra deps)	pip install vizzpy
SVG headless	pip install 'vizzpy[svg]'
Interactive web UI	pip install 'vizzpy[serve]'
Everything	pip install 'vizzpy[all]'

SVG rendering additionally requires the Graphviz system package:

# macOS
brew install graphviz

# Debian/Ubuntu
apt install graphviz

Usage

Web UI (recommended)

vizzpy --serve
# open http://127.0.0.1:8000

# or pre-load a local project — renders immediately on page open
vizzpy --serve --project ./myproject

Upload a .zip, .tar.gz, .egg, or .whl of your Python project, then click Analyze.

• Scroll / pinch to zoom
• Drag background to pan
• Drag nodes to rearrange
• Double-click a node to collapse/expand its call subtree (function view)
• Hover a node to see its docstring
• Function view / Module view button in the toolbar — toggle between individual function nodes and a rolled-up module-level graph

Headless rendering

# Mermaid markdown — no extra dependencies (default format)
vizzpy --headless --project ./myproject                          # → call_tree.md  (function level)
vizzpy --headless --project ./myproject --level module           # → call_tree.md  (module level)
vizzpy --headless --project ./myproject --level both             # → call_tree_functions.md + call_tree_modules.md

# SVG — requires Graphviz
vizzpy --headless --project ./myproject --format svg
vizzpy --headless --project ./myproject --format svg --level module
vizzpy --headless --project ./myproject --format svg --level both

# Custom output path
vizzpy --headless --project ./myproject --format mermaid --output graph.md

Options

vizzpy --serve   [--host HOST] [--port PORT] [--project PROJECT_PATH]
vizzpy --headless --project PROJECT_PATH [--format svg|mermaid] [--level function|module|both] [--output OUTPUT]

How it works

VizPy uses Python's ast module to do a two-pass analysis of your source files:

1. Scope pass — collects every top-level function and class method with its qualified name (module.ClassName.method)
2. Edge pass — walks each file again, resolves self.method(), cls.method(), imported names, and direct calls to project-internal functions

Results are rendered in the browser with dagre-d3 (vendored, works offline). Calls to explicitly imported library functions (e.g. pandas.read_csv) are shown as external leaf nodes — their internals are not traced.

Development

git clone https://github.com/atulsaurav/vizzpy
cd vizzpy
pip install -e ".[dev]"

# run tests
pytest

# run with coverage
pytest --cov=vizzpy --cov-report=term-missing

License

MIT