spielviz 0.1.1

Python visualization library for OpenSpiel game trees, information sets, and strategy profiles

spielviz

Python visualization library for OpenSpiel game trees, information sets, and strategy profiles.

Installation

pip install spielviz

Quick Start

import spielviz

# One-liner: render any OpenSpiel game
spielviz.quick_render("kuhn_poker", path="kuhn.png")

Or with more control:

import pyspiel
import spielviz

game = pyspiel.load_game("kuhn_poker")
root = spielviz.build_tree(game)
root = spielviz.layout_tree(root)

# Highlight information sets
colors = spielviz.auto_color_info_sets(root, player=0)
fig, ax = spielviz.render_tree(
    root,
    highlight_info_sets=colors,
    show_actions=True,
    show_payoffs=True,
    title="Kuhn Poker",
)
fig.savefig("kuhn_poker.png", dpi=150, bbox_inches="tight")

Features

Game Tree Rendering

Render any OpenSpiel game as a publication-quality tree diagram:

• Player-colored nodes (colorblind-friendly palette)
• Action labels on edges
• Terminal payoffs displayed
• Chance node probabilities

Information Set Visualization

Highlight which nodes a player cannot distinguish:

colors = spielviz.auto_color_info_sets(root, player=0)
fig, ax = spielviz.render_tree(root, highlight_info_sets=colors)

# Or draw dashed connection lines (standard game theory notation)
spielviz.draw_info_set_connections(ax, root, player=0)

Strategy Profile Visualization

Visualize policies from CFR, fictitious play, or any OpenSpiel algorithm:

from open_spiel.python.algorithms import cfr

solver = cfr.CFRSolver(game)
for _ in range(1000):
    solver.evaluate_and_update_policy()
policy = solver.average_policy()

# Bar chart of action probabilities at each info set
fig, ax = spielviz.plot_strategy_profile(game, policy, player=0)

# Strategy overlaid directly on the game tree
fig, ax = spielviz.plot_strategy_on_tree(root, game, policy, player=0)

Large Game Support

Use max_depth for games with large state spaces:

spielviz.quick_render("tic_tac_toe", max_depth=3, path="ttt.png")

API Reference

Function	Description
build_tree(game, max_depth=None)	Build a TreeNode hierarchy from an OpenSpiel game
layout_tree(root, algorithm="simple")	Compute (x, y) positions for all nodes
collect_info_sets(root)	Group nodes by information state string
render_tree(root, **kwargs)	Render game tree as matplotlib figure
save_tree(root, path, **kwargs)	Render and save to file (PNG, SVG, PDF)
auto_color_info_sets(root, player)	Assign distinct colors to info sets
draw_info_set_connections(ax, root, player)	Draw dashed lines between info set nodes
plot_strategy_profile(game, policy, player=0)	Bar chart of strategy at each info set
plot_strategy_on_tree(root, game, policy, player=0)	Mini bar charts overlaid on tree
quick_render(game_name, **kwargs)	One-liner convenience function

Tested Games

• kuhn_poker — 2-player Kuhn Poker
• leduc_poker — 2-player Leduc Poker (depth-limited)
• tic_tac_toe — Tic-Tac-Toe (depth-limited)

Contributing

Contributions welcome! Please open an issue or PR.

git clone https://github.com/kvr06-ai/spielviz.git
cd spielviz
pip install -e ".[dev]"
pytest tests/
ruff check src/

License

MIT