SDK for Assistant (#2266)

### What problem does this PR solve?

SDK for Assistant
#1102 

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

Co-authored-by: Feiue <10215101452@stu.ecun.edu.cn>

sdk/python/ragflow/modules/chat_assistant.py

@@ -0,0 +1,56 @@
+from .base import Base
+
+
+class Assistant(Base):
+    def __init__(self, rag, res_dict):
+        self.id=""
+        self.name = "assistant"
+        self.avatar = "path/to/avatar"
+        self.knowledgebases = ["kb1"]
+        self.llm = Assistant.LLM(rag, {})
+        self.prompt = Assistant.Prompt(rag, {})
+        super().__init__(rag, res_dict)
+
+    class LLM(Base):
+        def __init__(self, rag, res_dict):
+            self.model_name = "deepseek-chat"
+            self.temperature = 0.1
+            self.top_p = 0.3
+            self.presence_penalty = 0.4
+            self.frequency_penalty = 0.7
+            self.max_tokens = 512
+            super().__init__(rag, res_dict)
+
+    class Prompt(Base):
+        def __init__(self, rag, res_dict):
+            self.similarity_threshold = 0.2
+            self.keywords_similarity_weight = 0.7
+            self.top_n = 8
+            self.variables = [{"key": "knowledge", "optional": True}]
+            self.rerank_model = None
+            self.empty_response = None
+            self.opener = "Hi! I'm your assistant, what can I do for you?"
+            self.show_quote = True
+            self.prompt = (
+                "You are an intelligent assistant. Please summarize the content of the knowledge base to answer the question. "
+                "Please list the data in the knowledge base and answer in detail. When all knowledge base content is irrelevant to the question, "
+                "your answer must include the sentence 'The answer you are looking for is not found in the knowledge base!' "
+                "Answers need to consider chat history.\nHere is the knowledge base:\n{knowledge}\nThe above is the knowledge base."
+            )
+            super().__init__(rag, res_dict)
+
+    def save(self) -> bool:
+        res = self.post('/assistant/save',
+                        {"id": self.id, "name": self.name, "avatar": self.avatar, "knowledgebases":self.knowledgebases,
+                         "llm":self.llm.to_json(),"prompt":self.prompt.to_json()
+                         })
+        res = res.json()
+        if res.get("retmsg") == "success": return True
+        raise Exception(res["retmsg"])
+
+    def delete(self) -> bool:
+        res = self.rm('/assistant/delete',
+                      {"id": self.id})
+        res = res.json()
+        if res.get("retmsg") == "success": return True
+        raise Exception(res["retmsg"])