chore: Add pylint for storage (#1298)

dbgpt/storage/schema.py

@@ -1,14 +1,21 @@
+"""Database information class and database type enumeration."""
 import os
 from enum import Enum
+from typing import Optional
 
 
 class DbInfo:
+    """Database information class."""
+
     def __init__(self, name, is_file_db: bool = False):
+        """Create a new instance of DbInfo."""
         self.name = name
         self.is_file_db = is_file_db
 
 
 class DBType(Enum):
+    """Database type enumeration."""
+
     Mysql = DbInfo("mysql")
     OCeanBase = DbInfo("oceanbase")
     DuckDb = DbInfo("duckdb", True)
@@ -22,14 +29,24 @@ class DBType(Enum):
     Doris = DbInfo("doris")
     Hive = DbInfo("hive")
 
-    def value(self):
+    def value(self) -> str:
+        """Return the name of the database type."""
         return self._value_.name
 
-    def is_file_db(self):
+    def is_file_db(self) -> bool:
+        """Return whether the database is a file database."""
         return self._value_.is_file_db
 
     @staticmethod
-    def of_db_type(db_type: str):
+    def of_db_type(db_type: str) -> Optional["DBType"]:
+        """Return the database type of the given name.
+
+        Args:
+            db_type (str): The name of the database type.
+
+        Returns:
+            Optional[DBType]: The database type of the given name.
+        """
         for item in DBType:
             if item.value() == db_type:
                 return item
@@ -37,7 +54,7 @@ class DBType(Enum):
 
     @staticmethod
     def parse_file_db_name_from_path(db_type: str, local_db_path: str):
-        """Parse out the database name of the embedded database from the file path"""
+        """Parse out the database name of the embedded database from the file path."""
         base_name = os.path.basename(local_db_path)
         db_name = os.path.splitext(base_name)[0]
         if "." in db_name: