从tushare获取增减持数据

import tushare as ts
import pandas as pd
import numpy as np
import time
ts.set_token('xxx')
pro = ts.pro_api()
# 获取数据
start_date = '20190101'
end_date = '20190201'
sr_time = pd.date_range(start=start_date,end =end_date,freq='d')
periods= sr_time.shape[0]
print(periods)
tushare_data= pd.DataFrame()
for i in range(0,periods):
    trade_date=sr_time[i].strftime('%Y%m%d')
    print(trade_date)
    temp = pro.stk_holdertrade(ann_date=trade_date)
    tushare_data=tushare_data.append(temp)
    time.sleep(0.1)