diff --git a/04-CustomLibrary/ipandstring/stringip.py b/04-CustomLibrary/ipandstring/stringip.py
index 9a094ba..0ce0c44 100644
--- a/04-CustomLibrary/ipandstring/stringip.py
+++ b/04-CustomLibrary/ipandstring/stringip.py
@@ -52,12 +52,12 @@ class stringandip (object):
         print(ipStr)
         return ipStr
 
-    def getstring(self,randomlength=16):
+    def getstring(self,randomlength=16,base_str='ABCDEFGHIGKLMNOPQRSTUVWXYZabcdefghigklmnopqrstuvwxyz0123456789'):
         """
         生成一个指定长度的随机字符串
         """
         random_str = ''
-        base_str = 'ABCDEFGHIGKLMNOPQRSTUVWXYZabcdefghigklmnopqrstuvwxyz0123456789'
+        #base_str = 'ABCDEFGHIGKLMNOPQRSTUVWXYZabcdefghigklmnopqrstuvwxyz0123456789'
         length = len(base_str) - 1
         for i in range(randomlength):
             random_str += base_str[random.randint(0, length)]