diff --git a/tests/system-test/5-taos-tools/TD-12478.py b/tests/system-test/5-taos-tools/TD-12478.py
index 69849d3c7a7962955619a2674367402b5352376e..4328d65ba0883865bc7ed63b7acfddd659f5ea06 100644
--- a/tests/system-test/5-taos-tools/TD-12478.py
+++ b/tests/system-test/5-taos-tools/TD-12478.py
@@ -28,13 +28,13 @@ from itertools import combinations
 from faker import Faker
 import subprocess
 
+
 class TDTestCase:
     def caseDescription(self):
-        '''
-        case1<xyguo>[TD-12434]:taosdump null nchar/binary length can cause core:taos-tools/src/taosdump.c 
-        case2<xyguo>[TD-12478]:taos_stmt_execute() failed! reason: WAL size exceeds limit 
-        ''' 
-        return
+        """
+        case1<xyguo>[TD-12434]:taosdump null nchar/binary length can cause core:taos-tools/src/taosdump.c
+        case2<xyguo>[TD-12478]:taos_stmt_execute() failed! reason: WAL size exceeds limit
+        """
 
     def init(self, conn, logSql):
         tdLog.debug("start to execute %s" % __file__)
@@ -43,104 +43,184 @@ class TDTestCase:
         os.system("rm -rf 5-taos-tools/TD-12478.py.sql")
         os.system("rm db*")
         os.system("rm dump_result.txt*")
-    
+        os.system("rm -rf taosdump.*")
+
     def restartDnodes(self):
         tdDnodes.stop(1)
         tdDnodes.start(1)
 
-    def dropandcreateDB_random(self,n):
+    def dropandcreateDB_random(self, n):
         self.ts = 1630000000000
-        
-        fake = Faker('zh_CN')
+
+        fake = Faker("zh_CN")
         self.num_random = fake.random_int(min=1000, max=5000, step=1)
         print(self.num_random)
         for i in range(n):
-            tdSql.execute('''drop database if exists db ;''')
-            tdSql.execute('''create database db keep 36500;''')
-            tdSql.execute('''use db;''')
+            tdSql.execute("""drop database if exists db ;""")
+            tdSql.execute("""create database db keep 36500;""")
+            tdSql.execute("""use db;""")
 
-            tdSql.execute('''create stable stable_1 (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp , \
+            tdSql.execute(
+                """create stable stable_1 (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp , \
                     q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) \
-                    tags(loc nchar(100) , t_int int , t_bigint bigint , t_smallint smallint , t_tinyint tinyint, t_bool bool , t_binary binary(100) , t_nchar nchar(100) ,t_float float , t_double double , t_ts timestamp);''')
-            tdSql.execute('''create stable stable_2 (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp , \
+                    tags(loc nchar(100) , t_int int , t_bigint bigint , t_smallint smallint , t_tinyint tinyint, t_bool bool , t_binary binary(100) , t_nchar nchar(100) ,t_float float , t_double double , t_ts timestamp);"""
+            )
+            tdSql.execute(
+                """create stable stable_2 (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp , \
                     q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) \
-                    tags(loc nchar(100) , t_int int , t_bigint bigint , t_smallint smallint , t_tinyint tinyint, t_bool bool , t_binary binary(100) , t_nchar nchar(100) ,t_float float , t_double double , t_ts timestamp);''')
-            
-            tdSql.execute('''create table table_1 using stable_1 tags('table_1', '0' , '0' , '0' , '0' , 0 , '0' , '0' , '0' , '0' ,'0')''')
-            tdSql.execute('''create table table_2 using stable_1 tags('table_2', '2147483647' , '9223372036854775807' , '32767' , '127' , 1 , 'binary2' , 'nchar2' , '2' , '22' , \'1999-09-09 09:09:09.090\')''')
-            tdSql.execute('''create table table_3 using stable_1 tags('table_3', '-2147483647' , '-9223372036854775807' , '-32767' , '-127' , false , 'binary3' , 'nchar3nchar3' , '-3.3' , '-33.33' , \'2099-09-09 09:09:09.090\')''')
-            tdSql.execute('''create table table_21 using stable_2 tags('table_21' , '0' , '0' , '0' , '0' , 0 , '0' , '0' , '0' , '0' ,'0')''')
-
-            #regular table
-            tdSql.execute('''create table regular_table_1 \
+                    tags(loc nchar(100) , t_int int , t_bigint bigint , t_smallint smallint , t_tinyint tinyint, t_bool bool , t_binary binary(100) , t_nchar nchar(100) ,t_float float , t_double double , t_ts timestamp);"""
+            )
+
+            tdSql.execute(
+                """create table table_1 using stable_1 tags('table_1', '0' , '0' , '0' , '0' , 0 , '0' , '0' , '0' , '0' ,'0')"""
+            )
+            tdSql.execute(
+                """create table table_2 using stable_1 tags('table_2', '2147483647' , '9223372036854775807' , '32767' , '127' , 1 , 'binary2' , 'nchar2' , '2' , '22' , \'1999-09-09 09:09:09.090\')"""
+            )
+            tdSql.execute(
+                """create table table_3 using stable_1 tags('table_3', '-2147483647' , '-9223372036854775807' , '-32767' , '-127' , false , 'binary3' , 'nchar3nchar3' , '-3.3' , '-33.33' , \'2099-09-09 09:09:09.090\')"""
+            )
+            tdSql.execute(
+                """create table table_21 using stable_2 tags('table_21' , '0' , '0' , '0' , '0' , 0 , '0' , '0' , '0' , '0' ,'0')"""
+            )
+
+            # regular table
+            tdSql.execute(
+                """create table regular_table_1 \
                         (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp , \
-                        q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) ;''')
-            tdSql.execute('''create table regular_table_2 \
+                        q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) ;"""
+            )
+            tdSql.execute(
+                """create table regular_table_2 \
                         (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp , \
-                        q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) ;''')
-            tdSql.execute('''create table regular_table_3 \
+                        q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) ;"""
+            )
+            tdSql.execute(
+                """create table regular_table_3 \
                         (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp , \
-                        q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) ;''')
-
-
-            for i in range(self.num_random):        
-                tdSql.execute('''insert into table_1  (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double , q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d)''' 
-                            % (self.ts + i*1000, fake.random_int(min=-2147483647, max=2147483647, step=1), 
-                            fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
-                            fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
-                            fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.address() , self.ts + i))
-                tdSql.execute('''insert into  regular_table_1 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d)''' 
-                            % (self.ts + i*1000, fake.random_int(min=-2147483647, max=2147483647, step=1) , 
-                            fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1) , 
-                            fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
-                            fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.address() , self.ts + i))
-
-                tdSql.execute('''insert into table_2 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 1, 'binary.%s', 'nchar.%s', %d)''' 
-                            % (self.ts + i*1000, fake.random_int(min=0, max=2147483647, step=1), 
-                            fake.random_int(min=0, max=9223372036854775807, step=1), 
-                            fake.random_int(min=0, max=32767, step=1) , fake.random_int(min=0, max=127, step=1) , 
-                            fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.address() , self.ts + i))
-                tdSql.execute('''insert into regular_table_2 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 1, 'binary.%s', 'nchar.%s', %d)''' 
-                            % (self.ts + i*1000, fake.random_int(min=0, max=2147483647, step=1), 
-                            fake.random_int(min=0, max=9223372036854775807, step=1), 
-                            fake.random_int(min=0, max=32767, step=1) , fake.random_int(min=0, max=127, step=1) , 
-                            fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.address() , self.ts + i))
-
-                tdSql.execute('''insert into table_3 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d)''' 
-                            % (self.ts + i*1000, fake.random_int(min=-2147483647, max=0, step=1), 
-                            fake.random_int(min=-9223372036854775807, max=0, step=1), 
-                            fake.random_int(min=-32767, max=0, step=1) , fake.random_int(min=-127, max=0, step=1) , 
-                            fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.address() , self.ts + i))
-                tdSql.execute('''insert into regular_table_3 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 1, 'binary.%s', 'nchar.%s', %d)''' 
-                            % (self.ts + i*1000, fake.random_int(min=-2147483647, max=0, step=1), 
-                            fake.random_int(min=-9223372036854775807, max=0, step=1), 
-                            fake.random_int(min=-32767, max=0, step=1) , fake.random_int(min=-127, max=0, step=1) , 
-                            fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.address() , self.ts + i))
+                        q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) ;"""
+            )
+
+            for i in range(self.num_random):
+                tdSql.execute(
+                    """insert into table_1  (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double , q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d)"""
+                    % (
+                        self.ts + i * 1000,
+                        fake.random_int(min=-2147483647, max=2147483647, step=1),
+                        fake.random_int(
+                            min=-9223372036854775807, max=9223372036854775807, step=1
+                        ),
+                        fake.random_int(min=-32767, max=32767, step=1),
+                        fake.random_int(min=-127, max=127, step=1),
+                        fake.pyfloat(),
+                        fake.pyfloat(),
+                        fake.pystr(),
+                        fake.address(),
+                        self.ts + i,
+                    )
+                )
+                tdSql.execute(
+                    """insert into  regular_table_1 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d)"""
+                    % (
+                        self.ts + i * 1000,
+                        fake.random_int(min=-2147483647, max=2147483647, step=1),
+                        fake.random_int(
+                            min=-9223372036854775807, max=9223372036854775807, step=1
+                        ),
+                        fake.random_int(min=-32767, max=32767, step=1),
+                        fake.random_int(min=-127, max=127, step=1),
+                        fake.pyfloat(),
+                        fake.pyfloat(),
+                        fake.pystr(),
+                        fake.address(),
+                        self.ts + i,
+                    )
+                )
+
+                tdSql.execute(
+                    """insert into table_2 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 1, 'binary.%s', 'nchar.%s', %d)"""
+                    % (
+                        self.ts + i * 1000,
+                        fake.random_int(min=0, max=2147483647, step=1),
+                        fake.random_int(min=0, max=9223372036854775807, step=1),
+                        fake.random_int(min=0, max=32767, step=1),
+                        fake.random_int(min=0, max=127, step=1),
+                        fake.pyfloat(),
+                        fake.pyfloat(),
+                        fake.pystr(),
+                        fake.address(),
+                        self.ts + i,
+                    )
+                )
+                tdSql.execute(
+                    """insert into regular_table_2 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 1, 'binary.%s', 'nchar.%s', %d)"""
+                    % (
+                        self.ts + i * 1000,
+                        fake.random_int(min=0, max=2147483647, step=1),
+                        fake.random_int(min=0, max=9223372036854775807, step=1),
+                        fake.random_int(min=0, max=32767, step=1),
+                        fake.random_int(min=0, max=127, step=1),
+                        fake.pyfloat(),
+                        fake.pyfloat(),
+                        fake.pystr(),
+                        fake.address(),
+                        self.ts + i,
+                    )
+                )
+
+                tdSql.execute(
+                    """insert into table_3 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d)"""
+                    % (
+                        self.ts + i * 1000,
+                        fake.random_int(min=-2147483647, max=0, step=1),
+                        fake.random_int(min=-9223372036854775807, max=0, step=1),
+                        fake.random_int(min=-32767, max=0, step=1),
+                        fake.random_int(min=-127, max=0, step=1),
+                        fake.pyfloat(),
+                        fake.pyfloat(),
+                        fake.pystr(),
+                        fake.address(),
+                        self.ts + i,
+                    )
+                )
+                tdSql.execute(
+                    """insert into regular_table_3 (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts) values(%d, %d, %d, %d, %d, %f, %f, 1, 'binary.%s', 'nchar.%s', %d)"""
+                    % (
+                        self.ts + i * 1000,
+                        fake.random_int(min=-2147483647, max=0, step=1),
+                        fake.random_int(min=-9223372036854775807, max=0, step=1),
+                        fake.random_int(min=-32767, max=0, step=1),
+                        fake.random_int(min=-127, max=0, step=1),
+                        fake.pyfloat(),
+                        fake.pyfloat(),
+                        fake.pystr(),
+                        fake.address(),
+                        self.ts + i,
+                    )
+                )
 
             tdSql.query("select count(*) from stable_1;")
-            tdSql.checkData(0,0,3*self.num_random)
+            tdSql.checkData(0, 0, 3 * self.num_random)
             tdSql.query("select count(*) from regular_table_1;")
-            tdSql.checkData(0,0,self.num_random)
+            tdSql.checkData(0, 0, self.num_random)
 
     def run(self):
         tdSql.prepare()
 
         dcDB = self.dropandcreateDB_random(1)
-       
+
         assert os.system("taosdump -D db") == 0
 
         assert os.system("taosdump -i . -g") == 0
 
         tdSql.query("select count(*) from stable_1;")
-        tdSql.checkData(0,0,3*self.num_random)
+        tdSql.checkData(0, 0, 3 * self.num_random)
         tdSql.query("select count(*) from regular_table_1;")
-        tdSql.checkData(0,0,self.num_random)
+        tdSql.checkData(0, 0, self.num_random)
         tdSql.query("select count(*) from regular_table_2;")
-        tdSql.checkData(0,0,self.num_random)
+        tdSql.checkData(0, 0, self.num_random)
         tdSql.query("select count(*) from regular_table_3;")
-        tdSql.checkData(0,0,self.num_random)
-
-        
+        tdSql.checkData(0, 0, self.num_random)
 
     def stop(self):
         tdSql.close()
@@ -148,4 +228,4 @@ class TDTestCase:
 
 
 tdCases.addWindows(__file__, TDTestCase())
-tdCases.addLinux(__file__, TDTestCase())
\ No newline at end of file
+tdCases.addLinux(__file__, TDTestCase())