feat: add Finance tool for stock market data retrieval

[blueberrycongee]

Summary

Add a new Finance tool that retrieves real-time and historical stock market data using Yahoo Finance API.

Features

• 4 actions supported:

  • price - Get current stock price and trading info
  • history - Get historical price data
  • info - Get detailed company information
  • financials - Get financial statements summary

• Multi-market support:

  • US stocks (AAPL, GOOGL, MSFT)
  • Hong Kong stocks (9988.HK)
  • Chinese A-shares (600519.SS, 000001.SZ)

Changes

File	Description
qwen_agent/tools/finance.py	Finance tool implementation (~295 lines)
qwen_agent/tools/init.py	Export Finance class
setup.py	Add [finance] optional dependency (yfinance)
examples/assistant_finance_bot.py	Example usage
tests/tools/test_finance.py	Unit tests

Installation

pip install qwen-agent[finance]

[ycat3]

Thank you for nice work. It works fine.
However STOCK_dividends returns wrong value, 100 times bigger.
I also add cosmetic change.
See #754

[blueberrycongee]

@ycat3 Thank you for your feedback!

We have investigated the issue and found that while
yfinance
typically returns dividendYield as a decimal (e.g., 0.05 for 5%), there is a known upstream issue where Yahoo Finance data can sometimes be off by a factor of 100 (the "100x error"), causing it to appear as a percentage or larger.

To address this and ensure robustness, I've updated the code to handle both cases:

If the value is > 1, we treat it as a percentage (or an error-corrected value) and display it as is.
If the value is <= 1, we multiply by 100 to convert the decimal to a percentage.
This should resolve the discrepancy you observed while maintaining correctness for standard data.

@tuhahaha Could you please review these changes when you have a moment? Thanks!

[ycat3]

Thank you blueberrycongee and tuhahaha.
I have checked and it works fine.