Harrison/arxiv tool (#3186)

Co-authored-by: leo-gan <leo.gan.57@gmail.com>

langchain/tools/arxiv/__init__.py

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+"""Arxiv API toolkit."""

langchain/tools/arxiv/tool.py

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+"""Tool for the Wikipedia API."""
+
+from langchain.tools.base import BaseTool
+from langchain.utilities.arxiv import ArxivAPIWrapper
+
+
+class ArxivQueryRun(BaseTool):
+    """Tool that adds the capability to search using the Arxiv API."""
+
+    name = "Arxiv"
+    description = (
+        "A wrapper around Arxiv. "
+        "Useful for getting summary of articles from arxiv.org. "
+        "Input should be a search query."
+    )
+    api_wrapper: ArxivAPIWrapper
+
+    def _run(self, query: str) -> str:
+        """Use the Arxiv tool."""
+        return self.api_wrapper.run(query)
+
+    async def _arun(self, query: str) -> str:
+        """Use the Arxiv tool asynchronously."""
+        raise NotImplementedError("ArxivAPIWrapper does not support async")