community[minor]: add JsonRequestsWrapper tool (#15374)

**Description:** This new feature enhances the flexibility of pipeline
integration, particularly when working with RESTful APIs.
``JsonRequestsWrapper`` allows for the decoding of JSON output, instead
of the only option for text output.

---------

Co-authored-by: Zhichao HAN <hanzhichao2000@hotmail.com>

libs/community/langchain_community/utilities/requests.py

@@ -1,10 +1,11 @@
 """Lightweight wrapper around requests library, with async support."""
 from contextlib import asynccontextmanager
-from typing import Any, AsyncGenerator, Dict, Optional
+from typing import Any, AsyncGenerator, Dict, Literal, Optional, Union
 
 import aiohttp
 import requests
 from langchain_core.pydantic_v1 import BaseModel, Extra
+from requests import Response
 
 
 class Requests(BaseModel):
@@ -108,15 +109,13 @@ class Requests(BaseModel):
             yield response
 
 
-class TextRequestsWrapper(BaseModel):
-    """Lightweight wrapper around requests library.
-
-    The main purpose of this wrapper is to always return a text output.
-    """
+class GenericRequestsWrapper(BaseModel):
+    """Lightweight wrapper around requests library."""
 
     headers: Optional[Dict[str, str]] = None
     aiosession: Optional[aiohttp.ClientSession] = None
     auth: Optional[Any] = None
+    response_content_type: Literal["text", "json"] = "text"
 
     class Config:
         """Configuration for this pydantic object."""
@@ -130,50 +129,96 @@ class TextRequestsWrapper(BaseModel):
             headers=self.headers, aiosession=self.aiosession, auth=self.auth
         )
 
-    def get(self, url: str, **kwargs: Any) -> str:
+    def _get_resp_content(self, response: Response) -> Union[str, Dict[str, Any]]:
+        if self.response_content_type == "text":
+            return response.text
+        elif self.response_content_type == "json":
+            return response.json()
+        else:
+            raise ValueError(f"Invalid return type: {self.response_content_type}")
+
+    def _aget_resp_content(
+        self, response: aiohttp.ClientResponse
+    ) -> Union[str, Dict[str, Any]]:
+        if self.response_content_type == "text":
+            return response.text()
+        elif self.response_content_type == "json":
+            return response.json()
+        else:
+            raise ValueError(f"Invalid return type: {self.response_content_type}")
+
+    def get(self, url: str, **kwargs: Any) -> Union[str, Dict[str, Any]]:
         """GET the URL and return the text."""
-        return self.requests.get(url, **kwargs).text
+        return self._get_resp_content(self.requests.get(url, **kwargs))
 
-    def post(self, url: str, data: Dict[str, Any], **kwargs: Any) -> str:
+    def post(
+        self, url: str, data: Dict[str, Any], **kwargs: Any
+    ) -> Union[str, Dict[str, Any]]:
         """POST to the URL and return the text."""
-        return self.requests.post(url, data, **kwargs).text
+        return self._get_resp_content(self.requests.post(url, data, **kwargs))
 
-    def patch(self, url: str, data: Dict[str, Any], **kwargs: Any) -> str:
+    def patch(
+        self, url: str, data: Dict[str, Any], **kwargs: Any
+    ) -> Union[str, Dict[str, Any]]:
         """PATCH the URL and return the text."""
-        return self.requests.patch(url, data, **kwargs).text
+        return self._get_resp_content(self.requests.patch(url, data, **kwargs))
 
-    def put(self, url: str, data: Dict[str, Any], **kwargs: Any) -> str:
+    def put(
+        self, url: str, data: Dict[str, Any], **kwargs: Any
+    ) -> Union[str, Dict[str, Any]]:
         """PUT the URL and return the text."""
-        return self.requests.put(url, data, **kwargs).text
+        return self._get_resp_content(self.requests.put(url, data, **kwargs))
 
-    def delete(self, url: str, **kwargs: Any) -> str:
+    def delete(self, url: str, **kwargs: Any) -> Union[str, Dict[str, Any]]:
         """DELETE the URL and return the text."""
-        return self.requests.delete(url, **kwargs).text
+        return self._get_resp_content(self.requests.delete(url, **kwargs))
 
-    async def aget(self, url: str, **kwargs: Any) -> str:
+    async def aget(self, url: str, **kwargs: Any) -> Union[str, Dict[str, Any]]:
         """GET the URL and return the text asynchronously."""
         async with self.requests.aget(url, **kwargs) as response:
-            return await response.text()
+            return await self._aget_resp_content(response)
 
-    async def apost(self, url: str, data: Dict[str, Any], **kwargs: Any) -> str:
+    async def apost(
+        self, url: str, data: Dict[str, Any], **kwargs: Any
+    ) -> Union[str, Dict[str, Any]]:
         """POST to the URL and return the text asynchronously."""
         async with self.requests.apost(url, data, **kwargs) as response:
-            return await response.text()
+            return await self._aget_resp_content(response)
 
-    async def apatch(self, url: str, data: Dict[str, Any], **kwargs: Any) -> str:
+    async def apatch(
+        self, url: str, data: Dict[str, Any], **kwargs: Any
+    ) -> Union[str, Dict[str, Any]]:
         """PATCH the URL and return the text asynchronously."""
         async with self.requests.apatch(url, data, **kwargs) as response:
-            return await response.text()
+            return await self._aget_resp_content(response)
 
-    async def aput(self, url: str, data: Dict[str, Any], **kwargs: Any) -> str:
+    async def aput(
+        self, url: str, data: Dict[str, Any], **kwargs: Any
+    ) -> Union[str, Dict[str, Any]]:
         """PUT the URL and return the text asynchronously."""
         async with self.requests.aput(url, data, **kwargs) as response:
-            return await response.text()
+            return await self._aget_resp_content(response)
 
-    async def adelete(self, url: str, **kwargs: Any) -> str:
+    async def adelete(self, url: str, **kwargs: Any) -> Union[str, Dict[str, Any]]:
         """DELETE the URL and return the text asynchronously."""
         async with self.requests.adelete(url, **kwargs) as response:
-            return await response.text()
+            return await self._aget_resp_content(response)
+
+
+class JsonRequestsWrapper(GenericRequestsWrapper):
+    """Lightweight wrapper around requests library, with async support.
+
+    The main purpose of this wrapper is to always return a json output."""
+
+    response_content_type: Literal["text", "json"] = "json"
+
+
+class TextRequestsWrapper(GenericRequestsWrapper):
+    """Lightweight wrapper around requests library, with async support.
+
+    The main purpose of this wrapper is to always return a text output."""
+
+    response_content_type: Literal["text", "json"] = "text"
 
 
 # For backwards compatibility