优化代码，提高解耦

03_function_calling_tools/01_custom_function_calling.py

@@ -1,14 +1,10 @@
-import os
-from dotenv import load_dotenv
+from config import OPENAI_API_KEY
 from openai import OpenAI
 import json
 
-load_dotenv()
-
 
 def create_client():
-    api_key = os.getenv("OPENAI_API_KEY")
-    return OpenAI(api_key=api_key, base_url="https://api.deepseek.com")
+    return OpenAI(api_key=OPENAI_API_KEY, base_url="https://api.deepseek.com")
 
 def get_weather(location):
     # 模拟获得天气信息