如何让我的 Python 代码在网络断开时重新启动
How can I get my Python Code to restart when the network disconnects
我有一段 Python 代码 运行 作为通过 API 提取天气数据的服务。
当一切都很好时，代码本身运行得很好，即网络，但我注意到有时 Pi 上拉 API 数据的 WiFi 会掉线，然后 python代码似乎停止了。
我有一小行代码提供最基本的日志，但我想大大改进它。日志代码只为我提供了 datetime.now，所以我可以看到上次代码 运行 是什么时候。
#!/usr/bin/python3
#import modules
import cymysql
from time import sleep
from urllib.request import urlopen
import json
import datetime
#set MySQl Variables
host = "localhost"
user = "xxx"
password = "xxx"
schema = "xxx"
#connect to MySQL DB
db = cymysql.connect(host, user, password, schema)
curs = db.cursor()
#set api key for DarkSky API
apikey="xxx"
# Latitude & longitude
lati="-26.20227"
longi="28.04363"
# Add units=si to get it in sensible ISO units.
url="https://api.forecast.io/forecast/"+apikey+"/"+lati+","+longi+"?units=si"
#begin infinite loop
while True:
#convert API reading to json and readable array 'weather'
meteo=urlopen(url).read()
meteo = meteo.decode('utf-8')
weather = json.loads(meteo)
#set variables for current weather
cTemp = (weather['currently']['temperature'])
cCond = (weather['currently']['summary'])
cRain1 = (weather['currently']['precipProbability'])
cRain2 = cRain1*100
cIcon = (weather['currently']['icon'])
oaSum = (weather['daily']['summary'])
#print variables - for testing purposes
#print (cTemp)
#print (cCond)
#print (cRain2)
#print (cIcon)
#print (oaSum)
#extract daily data from 'weather' array
daily = (weather['daily']['data'])
#create new arrays for daily variables
listHigh = []
listLow = []
listCond = []
listRain = []
listIcon = []
#set daily variables
for i in daily:
listHigh.append(i['temperatureHigh'])
for i in range(0,len(listHigh)):
high1 = listHigh[0]
high2 = listHigh[1]
high3 = listHigh[2]
high4 = listHigh[3]
high5 = listHigh[4]
high6 = listHigh[5]
high7 = listHigh[6]
high8 = listHigh[7]
for o in daily:
listLow.append(o['temperatureLow'])
for o in range(0,len(listLow)):
low1 = listLow[0]
low2 = listLow[1]
low3 = listLow[2]
low4 = listLow[3]
low5 = listLow[4]
low6 = listLow[5]
low7 = listLow[6]
low8 = listLow[7]
for p in daily:
listCond.append(p['summary'])
for p in range(0,len(listCond)):
cond1 = listCond[0]
cond2 = listCond[1]
cond3 = listCond[2]
cond4 = listCond[3]
cond5 = listCond[4]
cond6 = listCond[5]
cond7 = listCond[6]
cond8 = listCond[7]
for m in daily:
listRain.append(m['precipProbability'])
for m in range(0,len(listRain)):
rain1 = listRain[0]
rain2 = listRain[1]
rain3 = listRain[2]
rain4 = listRain[3]
rain5 = listRain[4]
rain6 = listRain[5]
rain7 = listRain[6]
rain8 = listRain[7]
#convert rain chance to readable percentage
prain1 = rain1*100
prain2 = rain2*100
prain3 = rain3*100
prain4 = rain4*100
prain5 = rain5*100
prain6 = rain6*100
prain7 = rain7*100
prain8 = rain8*100
for l in daily:
listIcon.append(l['icon'])
for l in range (0,len(listIcon)):
icon1 = listIcon[0]
icon2 = listIcon[1]
icon3 = listIcon[2]
icon4 = listIcon[3]
icon5 = listIcon[4]
icon6 = listIcon[5]
icon7 = listIcon[6]
icon8 = listIcon[7]
#print daily variables - for testing purposes
#print (high1)
#print (low1)
#print (cond1)
#print (prain1)
#print (icon1)
#print (high2)
#print (low2)
#print (cond2)
#print (prain2)
#print (icon2)
#update data in DataBase
try:
sql_update_query = """UPDATE weather SET current_temp = %s, cur$
varis = (cTemp, cCond, cRain2, cIcon, high1, low1, cond1, prain$
curs.execute(sql_update_query, varis)
db.commit()
except db.Error as error:
print("Error: {}".format(error))
db.rollback()
#write date to log file
with open ("/home/pi/CoRo/Projects/WeatherMan/weatherlog.txt", mode="w") as file:
file.write('Last Data was pulled at: %s' %(datetime.datetime.now()))
#set loop to sleep for 10 minutes and go again
sleep(600)
我知道数据库代码被截断了，但这只是放入数据库的变量，我可以看到它有效。
但是，如果网络断开，代码将停止，数据库将保留最后轮询的 API 数据。
如果 API 获取失败，我将如何重新启动 python 代码？
提前致谢，
您可以重写代码中将天气数据提取为函数或单独模块的部分。这将允许您仅在网络连接正常时调用它。下面是一些伪代码：
if network_connection:
pull_weather_data()
else:
do_something()
do_something() 可能需要重新连接到网络，例如重置您的网络适配器。
您可以通过尝试 ping 您的路由器或外部 IP 来确定网络连接的状态，例如 Google 的 DNS 服务器（8.8.8.8 或 8.8.4.4）之一。
要避免嵌套循环，您可以使用 continue 子句。例如：
while True:
if network_connection:
pull_weather_data()
else:
reset_network_connection()
time.sleep(180) # Sleep for 3 minutes.
continue
continue 会将解释器发送回 while 循环的开始。它将从那里检查网络连接并提取数据或重置网络连接并再睡 3 分钟。
使用上面的 Quernons 答案编辑如下代码：
#!/usr/bin/python3
#import modules
import os
import cymysql
from time import sleep
from urllib.request import urlopen
import json
import datetime
#set MySQl Variables
host = "localhost"
user = "xxx"
password = "xxx"
schema = "xxx"
#connect to MySQL DB
db = cymysql.connect(host, user, password, schema)
curs = db.cursor()
#set api key for DarkSky API
apikey="xxx"
# Latitude & longitude
lati="-26.20227"
longi="28.04363"
# Add units=si to get it in sensible ISO units not stupid Fahreneheit.
url="https://api.forecast.io/forecast/"+apikey+"/"+lati+","+longi+"?units=si"
#begin infinite loop
while True:
#function to check if there is an internet connection
def check_ping():
hostname = "8.8.8.8"
response = os.system("ping -c 1 " + hostname)
#and then check the response...
if response == 0:
pingstatus = 0
else:
pingstatus = 1
return pingstatus
networkstatus = check_ping()
#print check_ping() - for testing purposes
#print (networkstatus)
#function to pull weather data from API
def get_weather():
#insert weather data here with no changes
if networkstatus == 0:
get_weather()
else:
print ("Resetting Network Adapters")
dwnnw = 'ifconfig wlan0 down'
upnw = 'ifconfig wlan0 up'
os.system(dwnnw)
os.system(upnw)
sleep(180)
continue
我有一段 Python 代码 运行 作为通过 API 提取天气数据的服务。
当一切都很好时，代码本身运行得很好，即网络，但我注意到有时 Pi 上拉 API 数据的 WiFi 会掉线，然后 python代码似乎停止了。
我有一小行代码提供最基本的日志，但我想大大改进它。日志代码只为我提供了 datetime.now，所以我可以看到上次代码 运行 是什么时候。
#!/usr/bin/python3
#import modules
import cymysql
from time import sleep
from urllib.request import urlopen
import json
import datetime
#set MySQl Variables
host = "localhost"
user = "xxx"
password = "xxx"
schema = "xxx"
#connect to MySQL DB
db = cymysql.connect(host, user, password, schema)
curs = db.cursor()
#set api key for DarkSky API
apikey="xxx"
# Latitude & longitude
lati="-26.20227"
longi="28.04363"
# Add units=si to get it in sensible ISO units.
url="https://api.forecast.io/forecast/"+apikey+"/"+lati+","+longi+"?units=si"
#begin infinite loop
while True:
#convert API reading to json and readable array 'weather'
meteo=urlopen(url).read()
meteo = meteo.decode('utf-8')
weather = json.loads(meteo)
#set variables for current weather
cTemp = (weather['currently']['temperature'])
cCond = (weather['currently']['summary'])
cRain1 = (weather['currently']['precipProbability'])
cRain2 = cRain1*100
cIcon = (weather['currently']['icon'])
oaSum = (weather['daily']['summary'])
#print variables - for testing purposes
#print (cTemp)
#print (cCond)
#print (cRain2)
#print (cIcon)
#print (oaSum)
#extract daily data from 'weather' array
daily = (weather['daily']['data'])
#create new arrays for daily variables
listHigh = []
listLow = []
listCond = []
listRain = []
listIcon = []
#set daily variables
for i in daily:
listHigh.append(i['temperatureHigh'])
for i in range(0,len(listHigh)):
high1 = listHigh[0]
high2 = listHigh[1]
high3 = listHigh[2]
high4 = listHigh[3]
high5 = listHigh[4]
high6 = listHigh[5]
high7 = listHigh[6]
high8 = listHigh[7]
for o in daily:
listLow.append(o['temperatureLow'])
for o in range(0,len(listLow)):
low1 = listLow[0]
low2 = listLow[1]
low3 = listLow[2]
low4 = listLow[3]
low5 = listLow[4]
low6 = listLow[5]
low7 = listLow[6]
low8 = listLow[7]
for p in daily:
listCond.append(p['summary'])
for p in range(0,len(listCond)):
cond1 = listCond[0]
cond2 = listCond[1]
cond3 = listCond[2]
cond4 = listCond[3]
cond5 = listCond[4]
cond6 = listCond[5]
cond7 = listCond[6]
cond8 = listCond[7]
for m in daily:
listRain.append(m['precipProbability'])
for m in range(0,len(listRain)):
rain1 = listRain[0]
rain2 = listRain[1]
rain3 = listRain[2]
rain4 = listRain[3]
rain5 = listRain[4]
rain6 = listRain[5]
rain7 = listRain[6]
rain8 = listRain[7]
#convert rain chance to readable percentage
prain1 = rain1*100
prain2 = rain2*100
prain3 = rain3*100
prain4 = rain4*100
prain5 = rain5*100
prain6 = rain6*100
prain7 = rain7*100
prain8 = rain8*100
for l in daily:
listIcon.append(l['icon'])
for l in range (0,len(listIcon)):
icon1 = listIcon[0]
icon2 = listIcon[1]
icon3 = listIcon[2]
icon4 = listIcon[3]
icon5 = listIcon[4]
icon6 = listIcon[5]
icon7 = listIcon[6]
icon8 = listIcon[7]
#print daily variables - for testing purposes
#print (high1)
#print (low1)
#print (cond1)
#print (prain1)
#print (icon1)
#print (high2)
#print (low2)
#print (cond2)
#print (prain2)
#print (icon2)
#update data in DataBase
try:
sql_update_query = """UPDATE weather SET current_temp = %s, cur$
varis = (cTemp, cCond, cRain2, cIcon, high1, low1, cond1, prain$
curs.execute(sql_update_query, varis)
db.commit()
except db.Error as error:
print("Error: {}".format(error))
db.rollback()
#write date to log file
with open ("/home/pi/CoRo/Projects/WeatherMan/weatherlog.txt", mode="w") as file:
file.write('Last Data was pulled at: %s' %(datetime.datetime.now()))
#set loop to sleep for 10 minutes and go again
sleep(600)
我知道数据库代码被截断了，但这只是放入数据库的变量，我可以看到它有效。
但是，如果网络断开，代码将停止，数据库将保留最后轮询的 API 数据。
如果 API 获取失败，我将如何重新启动 python 代码？
提前致谢，
您可以重写代码中将天气数据提取为函数或单独模块的部分。这将允许您仅在网络连接正常时调用它。下面是一些伪代码：
if network_connection:
pull_weather_data()
else:
do_something()
do_something() 可能需要重新连接到网络，例如重置您的网络适配器。
您可以通过尝试 ping 您的路由器或外部 IP 来确定网络连接的状态，例如 Google 的 DNS 服务器（8.8.8.8 或 8.8.4.4）之一。
要避免嵌套循环，您可以使用 continue 子句。例如：
while True:
if network_connection:
pull_weather_data()
else:
reset_network_connection()
time.sleep(180) # Sleep for 3 minutes.
continue
continue 会将解释器发送回 while 循环的开始。它将从那里检查网络连接并提取数据或重置网络连接并再睡 3 分钟。
使用上面的 Quernons 答案编辑如下代码：
#!/usr/bin/python3
#import modules
import os
import cymysql
from time import sleep
from urllib.request import urlopen
import json
import datetime
#set MySQl Variables
host = "localhost"
user = "xxx"
password = "xxx"
schema = "xxx"
#connect to MySQL DB
db = cymysql.connect(host, user, password, schema)
curs = db.cursor()
#set api key for DarkSky API
apikey="xxx"
# Latitude & longitude
lati="-26.20227"
longi="28.04363"
# Add units=si to get it in sensible ISO units not stupid Fahreneheit.
url="https://api.forecast.io/forecast/"+apikey+"/"+lati+","+longi+"?units=si"
#begin infinite loop
while True:
#function to check if there is an internet connection
def check_ping():
hostname = "8.8.8.8"
response = os.system("ping -c 1 " + hostname)
#and then check the response...
if response == 0:
pingstatus = 0
else:
pingstatus = 1
return pingstatus
networkstatus = check_ping()
#print check_ping() - for testing purposes
#print (networkstatus)
#function to pull weather data from API
def get_weather():
#insert weather data here with no changes
if networkstatus == 0:
get_weather()
else:
print ("Resetting Network Adapters")
dwnnw = 'ifconfig wlan0 down'
upnw = 'ifconfig wlan0 up'
os.system(dwnnw)
os.system(upnw)
sleep(180)
continue