How to insert data from Python program to MySQL database at intervals

Question

I have created a temperature sensor (using DS18B20 temperature sensor) and wrote the python program to read and display the temperature every 10 seconds. It worked fine. Later, I modified the code to save the recordings of each 10 sec to a MySQL database. Now, the problem is that it records AND uploads the data to the databse for the first time it reads. Then, I get an error message. So basically, the program reads and uploads to the database for once and then quits after the error. Please tell me how to fix this! Thanks a lot!

Here is the code:

import os
import time
import MySQLdb
import datetime

i = datetime.datetime.now()

db = MySQLdb.connect(host = "localhost", user = "root", passwd = "bb9125ap", db = "PY1")
cur = db.cursor()

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

temp_sensor = '/sys/bus/w1/devices/28-00042d6745ff/w1_slave'

def temp_raw():
    f = open(temp_sensor,'r')
    lines = f.readlines()
    f.close
    return lines

def read_temp():
    lines = temp_raw()
    while lines[0].strip()[-3:] != 'YES':
          time.sleep(0.2)
          lines = temp_raw()
    temp_output = lines[1].find('t=')
    if temp_output != -1:
          temp_string = lines[1].strip()[temp_output+2:]
          temp_c = float(temp_string) / 1000.0
          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)
          time = hour + ":" + minute + ":" + second

          try:
             cur.execute("""INSERT INTO PY1.DUMP1(temp_c,rec_time,rec_date) VALUES(%s,%s,%s)""",(valT,time,date))
             db.commit()
          except:
             db.rollback()

          time.sleep(10)

     cur.close()
     db.close()

Program name is temp1.py and line 54 according to my editor is db.rollback() Here is the error message I get

Traceback (most recent call last): File "temp1.py" , line 54 , in time.sleep(10) Attribute:'str' object has no attribute 'sleep'

Answer 1

您正在用本地变量时间覆盖导入的时间，并将其转换为字符串。

time = hour + ":" + minute + ":" + second