当我运行这个包含一些mysql的python代码时，我得到的只是三个较大或较小的符号（>>>）。任何帮助都将不胜感激！我的代码包括尝试通过ds18b20连接到我的raspberry pi 3获取温度，并将数据发送到我创建的mysql数据库中。
下面是python/mysql代码：

import os
import glob
import time
import MySQLdb
import datetime

i = datetime.datetime.now()

db = MySQLdb.connect(host = "127.0.0.1", user = "root", passwd = "test", db = "temp_pi")
cur = db.cursor()

os.system('modprobe w1-gpio')
os.system('modprobe w1-therm')

base_dir = '/sys/bus/w1/devices/'
device_folder = glob.glob(base_dir + '28*')[0]
device_file = device_folder + '/w1_slave'

def read_temp_raw():
    f = open(device_file, 'r')
    lines = f.readlines()
    f.close()
    return lines

def read_temp():
    lines = read_temp_raw()
    while lines[0].strip()[-3:] != 'YES':
        time.sleep(0.2)
        lines = read_temp_raw()
    equals_pos = lines[1].find('t=')
    if equals_pos != -1:
        temp_string = lines[1][equals_pos+2:]
        temp_c = float(temp_string) / 1000.0
        temp_f = temp_c * 9.0 / 5.0 + 32.0
        return temp_c
    while True:
          print ("recording data into database(period = 5s.)....press ctrl+Z to stop!")

          valT = str(read_temp())

          year = str(i.year)
          month = str(i.month)
          day = str(i.day)
          date = day + "-" + month + "-" + year

          hour = str(i.hour)
          minute = str(i.minute)
          second = str(i.second)
          timestr = hour + ":" + minute + ":" + second

          try:
             cur.execute("""INSERT INTO TAB_CLASSROOM(temp_c,T_Date,T_Time) VALUES(%s,%s,%s)""",(valT,date,time))
             db.commit()
          except:
             db.rollback()

          time.sleep(10)

    cur.close()  
    db.close()