Refactor and translate comments and docstrings in utility modules to English for better clarity and maintainability. Update Gunicorn and application startup messages for consistency in language. Enhance documentation with English translations for better accessibility.

backend_api_python/app/config/api_keys.py

@@ -5,8 +5,7 @@ All third-party keys should be provided via environment variables (recommended:
 import os
 
 class MetaAPIKeys(type):
-    """API Keys 元类，用于支持类属性的动态获取"""
-    
+    """API Keys metaclass, used to support dynamic acquisition of class attributes"""
     @property
     def FINNHUB_API_KEY(cls):
         from app.utils.config_loader import load_addon_config
@@ -95,18 +94,18 @@ class MetaAPIKeys(type):
 
 
 class APIKeys(metaclass=MetaAPIKeys):
-    """API 密钥配置类"""
-    
+    """API key configuration class"""
+
     @classmethod
     def get(cls, key_name: str, default: str = '') -> str:
-        """获取 API 密钥"""
-        # 尝试从类属性获取
+        """Get API key"""
+        # Try to get from class attribute
         if hasattr(cls, key_name):
             return getattr(cls, key_name)
         return default
     
     @classmethod
     def is_configured(cls, key_name: str) -> bool:
-        """检查 API 密钥是否已配置"""
+        """Check if the API key is configured"""
         value = cls.get(key_name)
         return bool(value and value.strip())