plotext-financial-chart_skill

Overview

This skill generates ASCII financial line charts for GitHub Flavored Markdown using plotext with the dot marker (•). It produces pure-text charts that render reliably in GitHub, terminals, and any monospace environment. The output is safe for inclusion in code blocks and paired with source in a <details> block for reproducible documentation.

How this skill works

The skill calls plotext to draw a line chart with marker="dot", sets a clear theme to avoid ANSI color codes, and uses plt.build() to capture the chart as a string. It strips any residual ANSI escape sequences, enforces mandatory settings (title, axis labels, plotsize, clear state), and returns a plain-text chart ready for embedding in Markdown. A small preflight script verifies plotext is available and that the dot marker renders as • before use.

When to use it

• Embedding price-path or trading charts directly in Markdown documentation
• Illustrating trading concepts like barriers, thresholds, or entry/exit levels
• Adding lightweight visualizations to READMEs, design notes, or issue discussions
• Creating terminal-friendly previews of financial data
• When you need reproducible, source-adjacent charts for examples or tutorials

Best practices

• Always call plt.clear_figure() before plotting to avoid stale state
• Use marker="dot" (•) — it aligns in GitHub code blocks and is the required default
• Apply plt.theme("clear") and strip ANSI escapes to ensure plain text output
• Use plt.build() (not plt.show()) and print the resulting string
• Include a title, xlabel, and ylabel for every chart and use plotsize 65x22 for 80-column code blocks
• Place the Python source inside a <details> block immediately after the chart

Example use cases

• Show a price path illustrating a triple-barrier backtest inside a README
• Document entry and exit thresholds for a trading strategy in a tutorial
• Embed a small time-series preview in an issue or design doc without images
• Produce terminal-friendly sample charts for interactive demos or unit-test artifacts