Yahoo Finance News tool (#10014)

Added:
- the `Yahoo Finance News` tool
- Ut-s
- An example

libs/langchain/langchain/tools/yahoo_finance_news.py

@@ -0,0 +1,67 @@
+from typing import Iterable, Optional
+
+from requests.exceptions import HTTPError, ReadTimeout
+from urllib3.exceptions import ConnectionError
+
+from langchain.callbacks.manager import CallbackManagerForToolRun
+from langchain.document_loaders.web_base import WebBaseLoader
+from langchain.schema import Document
+from langchain.tools.base import BaseTool
+
+
+class YahooFinanceNewsTool(BaseTool):
+    """Tool that searches financial news on Yahoo Finance."""
+
+    name: str = "yahoo_finance_news"
+    description: str = (
+        "Useful for when you need to find financial news "
+        "about a public company. "
+        "Input should be a company ticker. "
+        "For example, AAPL for Apple, MSFT for Microsoft."
+    )
+    top_k: int = 10
+    """The number of results to return."""
+
+    def _run(
+        self,
+        query: str,
+        run_manager: Optional[CallbackManagerForToolRun] = None,
+    ) -> str:
+        """Use the Yahoo Finance News tool."""
+        try:
+            import yfinance
+        except ImportError:
+            raise ImportError(
+                "Could not import yfinance python package. "
+                "Please install it with `pip install yfinance`."
+            )
+        company = yfinance.Ticker(query)
+        try:
+            if company.isin is None:
+                return f"Company ticker {query} not found."
+        except (HTTPError, ReadTimeout, ConnectionError):
+            return f"Company ticker {query} not found."
+
+        links = []
+        try:
+            links = [n["link"] for n in company.news if n["type"] == "STORY"]
+        except (HTTPError, ReadTimeout, ConnectionError):
+            if not links:
+                return f"No news found for company that searched with {query} ticker."
+        if not links:
+            return f"No news found for company that searched with {query} ticker."
+        loader = WebBaseLoader(links)
+        docs = loader.load()
+        result = self._format_results(docs, query)
+        if not result:
+            return f"No news found for company that searched with {query} ticker."
+        return result
+
+    @staticmethod
+    def _format_results(docs: Iterable[Document], query: str) -> str:
+        doc_strings = [
+            "\n".join([doc.metadata["title"], doc.metadata["description"]])
+            for doc in docs
+            if query in doc.metadata["description"] or query in doc.metadata["title"]
+        ]
+        return "\n\n".join(doc_strings)

libs/langchain/tests/integration_tests/tools/test_yahoo_finance_news.py

@@ -0,0 +1,31 @@
+import pytest
+
+from langchain.tools.yahoo_finance_news import YahooFinanceNewsTool
+
+# skip all tests if yfinance is not installed
+yfinance = pytest.importorskip("yfinance")
+
+
+def test_success() -> None:
+    """Test that the tool runs successfully."""
+    tool = YahooFinanceNewsTool()
+    query = "Microsoft"
+    result = tool.run(query)
+    assert result is not None
+    assert f"Company ticker {query} not found." not in result
+
+
+def test_failure_no_ticker() -> None:
+    """Test that the tool fails."""
+    tool = YahooFinanceNewsTool()
+    query = ""
+    result = tool.run(query)
+    assert f"Company ticker {query} not found." in result
+
+
+def test_failure_wrong_ticker() -> None:
+    """Test that the tool fails."""
+    tool = YahooFinanceNewsTool()
+    query = "NOT_A_COMPANY"
+    result = tool.run(query)
+    assert f"Company ticker {query} not found." in result