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/utils/cache.py

@@ -15,7 +15,7 @@ logger = get_logger(__name__)
 
 
 class MemoryCache:
-    """内存缓存（Redis 不可用时的备选方案）"""
+    """In-memory cache (an alternative if Redis is unavailable)"""
     
     def __init__(self):
         self._cache = {}
@@ -47,7 +47,7 @@ class MemoryCache:
 
 
 class CacheManager:
-    """缓存管理器"""
+    """cache manager"""
     
     _instance = None
     _lock = threading.Lock()
@@ -98,7 +98,7 @@ class CacheManager:
             self._use_redis = False
     
     def get(self, key: str) -> Optional[Any]:
-        """获取缓存"""
+        """Get cache"""
         try:
             data = self._client.get(key)
             if data:
@@ -109,14 +109,14 @@ class CacheManager:
             return None
     
     def set(self, key: str, value: Any, ttl: int = 300):
-        """设置缓存"""
+        """Set up cache"""
         try:
             self._client.setex(key, ttl, json.dumps(value))
         except Exception as e:
             logger.error(f"Cache write failed: {e}")
     
     def delete(self, key: str):
-        """删除缓存"""
+        """Delete cache"""
         try:
             self._client.delete(key)
         except Exception as e: