Market Data Automation

A Python command-line project that retrieves or loads historical price data, calculates reproducible closing-price statistics, and exports CSV, JSON, and Markdown reports.

Educational project: outputs are historical-data summaries, not investment advice, price forecasts, or trading recommendations.

Project History

This project began as a college automation exercise created without AI assistance. The original repository was later lost, and only one recovered script remained. That script is preserved unchanged in legacy/Stockbot_original.py.

The current version rebuilds the original idea with testable modules, offline execution, explicit validation, and local report generation. See Recovery and Modernization Notes for the technical comparison.

日本語概要

Market Data Automation は、過去の市場価格データを取得またはCSVから読み込み、終値の統計を計算し、CSV・JSON・Markdown形式のレポートを生成するPython CLIプロジェクトです。

本プロジェクトは学習・ポートフォリオ目的です。投資助言、価格予測、売買推奨を提供するものではありません。

Features

• B3 symbols with automatic .SA suffix support;
• global Yahoo Finance symbols such as AAPL or 7203.T;
• inclusive start and exclusive end-date validation;
• online historical data through yfinance.Ticker.history();
• offline CSV mode for repeatable demonstrations;
• minimum, maximum, average, median, and period change calculations;
• raw-history CSV export;
• machine-readable JSON summary;
• human-readable Markdown report;
• automated tests that do not require network access.

Requirements

• Python 3.10+
• internet access only for Yahoo Finance mode.

Installation

git clone https://github.com/artloock/MarketDataAutomation.git
cd MarketDataAutomation
python -m venv .venv

Activate the virtual environment on Windows:

.venv\Scripts\Activate.ps1

Install dependencies:

python -m pip install -r requirements.txt

Offline Demonstration

The included sample allows the complete workflow to run without internet access:

python -m market_data_automation.cli \
  --ticker SAMPLE \
  --market global \
  --input-csv examples/sample_prices.csv \
  --output-dir output/sample

PowerShell version:

python -m market_data_automation.cli `
  --ticker SAMPLE `
  --market global `
  --input-csv examples/sample_prices.csv `
  --output-dir output/sample

Yahoo Finance Examples

B3 symbol:

python -m market_data_automation.cli \
  --ticker PETR4 \
  --market b3 \
  --start 2025-01-01 \
  --end 2026-01-01 \
  --output-dir output/petr4

Global symbol:

python -m market_data_automation.cli \
  --ticker AAPL \
  --market global \
  --start 2025-01-01 \
  --end 2026-01-01 \
  --output-dir output/aapl

The end date follows the yfinance historical-data convention and is exclusive.

Generated Files

Each execution creates:

TICKER_history.csv
TICKER_summary.json
TICKER_report.md

Prices remain in the instrument's source currency. The project does not perform currency conversion.

Input CSV Format

Offline data must contain at least Date and Close:

Date,Close
2026-01-05,30.50
2026-01-06,31.75

Additional OHLCV columns are preserved in the exported history.

Tests

python -m unittest discover -s tests -v

Tests use local sample data and generated DataFrames. They do not contact Yahoo Finance.

Reliability Improvements

The recovered version controlled Gmail through fixed screen coordinates. That approach depended on resolution, browser layout, language, login state, and timing.

The modernized version:

• separates collection, analysis, and reporting;
• produces files instead of clicking a browser;
• validates inputs before fetching data;
• supports a deterministic offline mode;
• returns process exit codes;
• preserves the recovered script for historical comparison.

Limitations

• Yahoo Finance availability and returned data are outside this project's control;
• only historical daily data is analyzed;
• corporate actions, taxes, inflation, fees, dividends, and currency conversion are not modeled;
• statistics describe the selected period and do not predict future performance;
• reports should be independently verified before any consequential use.

Data Source

Online mode uses the public Ticker.history() interface from yfinance. The library provides access to Yahoo Finance market data but is not affiliated with or endorsed by Yahoo.

License and Attribution

Released under the MIT License. Copies or substantial portions must retain the original copyright and license notice.

Author

Arthur Alves Stefanini GitHub · LinkedIn