diff --git a/pymysqlpool/pool.py b/pymysqlpool/pool.py
index b511de9..fab4a1e 100644
--- a/pymysqlpool/pool.py
+++ b/pymysqlpool/pool.py
@@ -64,7 +64,7 @@ def __init__(self,
                  host="localhost",
                  port=3306,
                  user=None,
-                 password=None,
+                 password: str | None = None,
                  unix_socket=None,
                  db=None,
                  charset="utf8",
@@ -78,7 +78,7 @@ def __init__(self,
                  multiple=4,
                  counter=0,
                  accumulation=0,
-                 ping_check: (int, bool) = False,
+                 ping_check: int | bool = False,
                  **configs):
         self.host = host
         self.port = port
@@ -115,7 +115,7 @@ def create_conn(self):
             host=self.host,
             port=self.port,
             user=self.user,
-            password=self.password,
+            password=self.password or "",
             db=self.db,
             charset=self.charset,
             cursorclass=self.cursorclass,
@@ -182,10 +182,12 @@ def __get_safe_conn(self, retry_count):
                 if c.__ping_check_timestamp < timeout:
                     c.__ping_check_timestamp = now
                     c.ping()
-            except:
+            except Exception:
                 self.current_size -= 1
-                if retry_count < 10: c = self.__get_conn(retry_count+1)
-        if c: self.inuse_list.add(c)
+                if retry_count < 10:
+                    c = self.__get_conn(retry_count+1)
+        if c:
+            self.inuse_list.add(c)
         return c
 
     def get_pool_size(self):