我按照 https://gitee.com/dolphindb/Tutorials_CN/blob/master/OHLC.md#/dolphindb/Tutorials_CN/blob/master/data/k-line/trades.csv  教程试验

```

In [105]: import dolphindb as ddb             
     ...: import pandas as pd                 
     ...: import numpy as np                  
     ...: csv_file = "trades.csv"             
     ...: csv_data = pd.read_csv(csv_file, dtype={'Symbol':str} )                            
     ...: csv_df = pd.DataFrame(csv_data)     
     ...: s = ddb.session();                  
     ...: s.connect("127.0.0.1",8848,"admin","123456")                                       
     ...: #上传DataFrame到DolphinDB，并对Datetime字段做类型转换                              
     ...: s.upload({"tmpData":csv_df})        
     ...: s.run("data = select Symbol, datetime(Datetime) as Datetime, Price, Volume from tmpData")         

 s.run(''' share streamTable(100:0, `Symbol`Datetime`Price`Volume,[SYMBOL,DATETIME,DOUBLE,INT]) as Trade ''')                                                                                

In [110]: s.run("tableInsert(Trade,data)")    
Out[110]: 31196                   

In [117]: s.run('''                           
     ...: share keyedStreamTable(`datetime`Symbol, 100:0, `datetime`Symbol`open`high`low`close`volume,[DATETIME,SYMBOL,DOUBLE,DOUBLE,DOUBLE,DOUBLE,LONG]) as OHLC                         
     ...: tsAggr = createTimeSeriesAggregator(name="tsAggr", windowSize=60, step=60, metrics=<[first(Price),max(Price),min(Price),last(Price),sum(volume)]>, dummyTable=Trade, outputTable
     ...: =OHLC, timeColumn=`Datetime, keyColumn=`Symbol, updateTime=1, useWindowStartTime=true)                                                                                          
     ...: subscribeTable(tableName="Trade", actionName="act_tsaggr", offset=0, handler=append!{tsAggr}, msgAsTable=true);                                                                 
     ...:                                     
     ...:                                                                                                
     ...: ''')               
Out[117]: 'localhost:8848:local8848/Trade/act_tsaggr'                                        

In [118]: try:                                
     ...:     s.enableStreaming(20001)        
     ...: except Exception as e:              
     ...:     print(s,e)                      
     ...: def handler(lst):                   
     ...:     print(lst)                      
     ...: # 订阅DolphinDB(本机8848端口)上的OHLC流数据表                                      
     ...: s.subscribe("127.0.0.1", 8848, handler, "OHLC5","python_api_subscribe",0)          
     ...: Event().wait()                      
<dolphindb.session.session object at 0x7f1557db9130> streaming is already enabled            
---------------------------------------------------------------------------                  
RuntimeError                              Traceback (most recent call last)                  
<ipython-input-118-0b700c0dd762> in <module>  
      6     print(lst)                        
      7 # 订阅DolphinDB(本机8848端口)上的OHLC流数据表                                        
----> 8 s.subscribe("127.0.0.1", 8848, handler, "OHLC","python_api_subscribe",0)            
      9 Event().wait()                        

~/.local/lib/python3.8/site-packages/dolphindb/session.py in subscribe(self, host, port, handler, tableName, actionName, offset, resub, filter, msgAsTable, batchSize, throttle, userName, password, streamDeserializer)                
    424             if msgAsTable:            
    425                 raise ValueError("msgAsTable must be False when batchSize is 0")     
--> 426             self.cpp.subscribe(host, port, handler, tableName, actionName, offset, resub, filter,userName,password,sd)                                                            
    427                                       
    428     ##                                

RuntimeError: 127.0.0.1:8848 Server response: 'Failed to add publishing request to the asynchronous publisher' script: 'publishTable'            

```

按照 @wfHuang2 还是出错

 s.enableStreaming(0)

~/.local/lib/python3.8/site-packages/dolphindb/session.py in enableStreaming(self, port, threadCount)
    387     #@endif
    388     def enableStreaming(self, port, threadCount = 1):
--> 389         self.cpp.enableStreaming(port,threadCount)
    390 
    391     ##

RuntimeError: streaming is already enabled