[Mem0] Update dependencies and make the package lighter (#1708)

Co-authored-by: Dev-Khant <devkhant24@gmail.com>

mem0/llms/litellm.py

@@ -1,7 +1,12 @@
 import json
 from typing import Dict, List, Optional
 
-import litellm
+try:
+    import litellm
+except ImportError:
+    raise ImportError(
+        "litellm requires extra dependencies. Install with `pip install litellm`"
+    ) from None
 
 from mem0.llms.base import LLMBase
 from mem0.configs.llms.base import BaseLlmConfig
@@ -12,8 +17,8 @@ class LiteLLM(LLMBase):
         super().__init__(config)
 
         if not self.config.model:
-            self.config.model="gpt-4o"
-    
+            self.config.model = "gpt-4o"
+
     def _parse_response(self, response, tools):
         """
         Process the response based on whether tools are used or not.
@@ -28,16 +33,18 @@ class LiteLLM(LLMBase):
         if tools:
             processed_response = {
                 "content": response.choices[0].message.content,
-                "tool_calls": []
+                "tool_calls": [],
             }
-            
+
             if response.choices[0].message.tool_calls:
                 for tool_call in response.choices[0].message.tool_calls:
-                    processed_response["tool_calls"].append({
-                        "name": tool_call.function.name,
-                        "arguments": json.loads(tool_call.function.arguments)
-                    })
-            
+                    processed_response["tool_calls"].append(
+                        {
+                            "name": tool_call.function.name,
+                            "arguments": json.loads(tool_call.function.arguments),
+                        }
+                    )
+
             return processed_response
         else:
             return response.choices[0].message.content
@@ -62,14 +69,16 @@ class LiteLLM(LLMBase):
             str: The generated response.
         """
         if not litellm.supports_function_calling(self.config.model):
-            raise ValueError(f"Model '{self.config.model}' in litellm does not support function calling.")
+            raise ValueError(
+                f"Model '{self.config.model}' in litellm does not support function calling."
+            )
 
         params = {
-            "model": self.config.model, 
-            "messages": messages, 
-            "temperature": self.config.temperature, 
-            "max_tokens": self.config.max_tokens, 
-            "top_p": self.config.top_p
+            "model": self.config.model,
+            "messages": messages,
+            "temperature": self.config.temperature,
+            "max_tokens": self.config.max_tokens,
+            "top_p": self.config.top_p,
         }
         if response_format:
             params["response_format"] = response_format