Python Lirc即使在禁用阻塞时也会阻塞代码

我正在运行最新的Rasbian Wheeezy发行版，试图在我的Raspberry Pi B+上使用自己的开放天气网络（Open weather Network）设置滚动天气提要，我在使用Python LIRC（Linux红外线遥控器）添加红外支持时遇到问题

我想做什么： 有四个天气变量：条件、温度、湿度和风速。它们将出现在我的16x2 LCD屏幕上，标题在顶行居中，值在第二行居中。它们将在屏幕上停留五秒钟，然后被下一个替换。一旦到达终点，它将再次循环。经过180次循环（大约1小时）后，它将更新天气。我想使用我的红外遥控器的按钮1-4跳转到一个特定的磁贴，然后继续它的循环

它在做什么： 当没有按下按钮时，它不会像关闭LIRC阻塞时那样跳过空队列，而是挂起LIRC.nextcode（）等待按下按钮，直到我使用键盘中断退出

在我添加IR之前，一切都很顺利。现在它显示第一个天气变量，然后当它尝试拉取下一个天气变量时，lirc.nextcode（）停止代码，直到它收到一个IR代码，而不是在队列中没有IR代码时跳过并转到下一个磁贴，lirc阻塞关闭时不应该发生这种情况

我有所有东西的最新版本（pythonlirc 1.2.1），我知道以前版本的pythonlirc有一个带有阻塞参数的bug。我花了两天时间研究并尝试了所有可能的事情。我发现了一个可能的解决方法，但它受到与此相同的问题的影响：“

我知道很多代码是不合适的，比如全局变量，函数中需要有东西，每三个小时更新一次，我每一个小时更新一次，但这只是暂时的。我稍后会整理它并使其成为面向对象的。如果这让一些人阅读起来更困难，请提前道歉

import pyowm
from sys import exit
import time
import RPi.GPIO as GPIO
from RPLCD import CharLCD, cleared, cursor
import lirc

# initialize lirc and turn of blocking
sockid = lirc.init("weather", blocking=False)
lirc.set_blocking(False, sockid)

# initialize weather network
owm = pyowm.OWM('API #')

# initialize LCD
lcd = CharLCD(pin_rs=26, pin_rw=None, pin_e=24, pins_data=[22, 18, 16, 12],
                  cols=16, rows=2)

# weather data
w = None # wind m/s
wind = None # wind km/h
windkm = None
humidity = None
temper = None
COUNTER = 0 #number of cycles before update

NEXT = 1

# switches to next tile
def next_tile():
    global NEXT

这就是问题所在Lirc.nextcode（）应拉取下一个IR 从LIRC队列编码，并将其作为列表添加到codeIR，如果没有 按钮已按下，且阻塞已关闭，应跳过 密码。相反，它的行为就像阻塞已打开一样，并一直挂起，直到 按下一个按钮。然后它仍然不会继续我的主循环。信息技术 只需打印下一个并挂起，直到I键盘中断退出

    codeIR = lirc.nextcode() # pulls IR code from LIRC queue.
    # checks if there's a code in codeIR and goes to that tile. If not, it 
    # goes to the next tile instead.
    if not codeIR: 
        if NEXT != 4: # if it's the last tile, cycle to the first 
            NEXT += 1
            print NEXT
            return NEXT
        else: # if not last tile, go to next
            NEXT -= 3
            print NEXT
            return NEXT
    else:
        NEXT = codeIR[0]
        print NEXT
        return NEXT

我已经添加了我的代码的其余部分，它们都可以正常工作，但我相信它会帮助您理解我试图实现的目标

while True:
    try:
        if COUNTER == 0:
            COUNTER = 180

            # Search for current weather in London (UK)
            observation = owm.weather_at_place('City, State')
            w = observation.get_weather()

            # Weather details
            wind = w.get_wind()                  # {'speed': 4.6, 'deg': 330}
            windkm = (wind['speed'] * 3600) / 1000 #convet to km/h
            humidity = w.get_humidity() 
            # {'temp_max': 10.5, 'temp': 9.7, 'temp_min': 9.0}
            temper = w.get_temperature('celsius')  
        else:
            while NEXT == 1:
                # prints condition to lcd
                lcd.cursor_pos = (0, 4) #adjust cursor position
                lcd.write_string('Weather') # write to lcd
                lcd.cursor_pos = (1, 5) # adjust cursor position
                lcd.write_string(w.get_status()) # write to lcd
                time.sleep(5) # leave on lcd for 5 seconds
                lcd.clear() # clear lcd
                next_tile() # switches to next tile

            while NEXT == 2:
                # prints temp to lcd
                lcd.cursor_pos = (0, 2)
                lcd.write_string('Temperature')
                lcd.cursor_pos = (1, 6)
                lcd.write_string(str(temper['temp']))
                lcd.write_string(' C')
                time.sleep(5)
                lcd.clear()
                next_tile()

            while NEXT == 3:
                # prints temp to lcd
                lcd.cursor_pos = (0, 4)
                lcd.write_string('Humidity')
                lcd.cursor_pos = (1, 6)
                lcd.write_string(str(humidity))
                lcd.write_string(' %')
                time.sleep(5)
                lcd.clear()
                next_tile()

            while NEXT == 4:
                # prints wind speed to lcd
                lcd.cursor_pos = (0, 3)
                lcd.write_string('Wind Speed')
                lcd.cursor_pos = (1, 6)
                lcd.write_string(str(int(windkm)))
                lcd.write_string('km')
                time.sleep(5)
                lcd.clear()
                COUNTER -= 1
                codeIR = lirc.nextcode()
                next_tile()

    # quit with ctrl+C
    except(KeyboardInterrupt, SystemExit):
        print 'quitting'
        lcd.close(clear=True)
        lirc.deinit()
        exit()

当我键盘中断退出时，回溯总是导致lirc.nextcode（），我会发布错误，但我稍微更改了代码，现在它只跟踪到包含lirc.nextcode（）的函数

---

我花了两天的时间试图解决这个问题，我几乎要拔头发了，所以我会采取你们能给我的任何解决方案或解决办法。事先谢谢，我真的很感激能找到的任何帮助。我找到了一个解决办法，使用了信号模块AlarmException，但当我从原始输入（）切换到lirc.nextcode（）时，它也以同样的方式挂起（即使它在原始输入（）上设置了计时器，也没有问题），并阻止了警报正常工作。这里又是一个链接：“

我想这个bug仍然在1.2.1中。我切换到pyrirc 2，它关闭了阻塞功能pyrirc没有问题。阻塞（0）。我还必须从我的next_tile（）函数中删除

return

下面是我最终使用的完成代码，如果有人感兴趣，它肯定会为我节省大量时间：

import pyowm
from sys import exit
import time
import RPi.GPIO as GPIO, feedparser, time
from RPLCD import CharLCD, cleared, cursor
import pylirc

sockid = pylirc.init('weather')
allow = pylirc.blocking(0)
owm = pyowm.OWM('API Key')
lcd = CharLCD(pin_rs=26, pin_rw=None, pin_e=24, pins_data=[22, 18, 16, 12],
                  cols=16, rows=2)


class mail(object):
    def __init__(self):
        self.username = "email address"    
        self.password = "password"
        self.newmail_offset = 0
        self.current = 0
        GPIO.setmode(GPIO.BOARD)
        GPIO.setup(15, GPIO.OUT)
        GPIO.setup(13, GPIO.OUT)
        GPIO.setup(11, GPIO.OUT)

    def buzz(self):
        self.period = 1.0 / 250
        self.delay = self.period / 2
        self.cycles = 250

        for i in range(self.cycles):
            GPIO.output(11, True)
            time.sleep(self.delay)

            GPIO.output(11, False)
            time.sleep(self.delay)

    def check(self): 
        self.newmails = int(feedparser.parse("https://" + self.username + ":" + 
                            self.password +"@mail.google.com/gmail/feed/atom")
                            ["feed"]["fullcount"])

        if self.newmails > self.newmail_offset:
            GPIO.output(15, True)
            GPIO.output(13, False)

            if self.newmails > self.current:
                self.buzz()
                self.current += 1    
        else:
            GPIO.output(15, False)
            GPIO.output(13, True)
            self.current = 0

### will be a class
class weather(object):
    def __init__(self):
        self.w = None
        self.wind = None
        self.windkm = None
        self.humidity = None
        self.temper = None
        self.counter = 0
        self.next = 1

    def update(self):
        if self.counter == 0:
            self.counter = 180
            self.observation = owm.weather_at_place('City, Country')
            self.w = self.observation.get_weather()
            self.wind = self.w.get_wind()
            self.windkm = (self.wind['speed'] * 3600) / 1000
            self.humidity = self.w.get_humidity()
            self.temper = self.w.get_temperature('celsius')
        else:
            pass

    def display_weather(self):
        lcd.cursor_pos = (0, 4)
        lcd.write_string('Weather')
        lcd.cursor_pos = (1, 5)
        lcd.write_string(self.w.get_status())
        time.sleep(3)
        lcd.clear()

    def display_temp(self):
        lcd.cursor_pos = (0, 2)
        lcd.write_string('Temperature')
        lcd.cursor_pos = (1, 6)
        lcd.write_string(str(self.temper['temp']))
        lcd.write_string(' C')
        time.sleep(3)
        lcd.clear()

    def display_hum(self):
        lcd.cursor_pos = (0, 4)
        lcd.write_string('Humidity')
        lcd.cursor_pos = (1, 6)
        lcd.write_string(str(self.humidity))
        lcd.write_string(' %')
        time.sleep(3)
        lcd.clear()

    def display_wind(self):
        lcd.cursor_pos = (0, 3)
        lcd.write_string('Wind Speed')
        lcd.cursor_pos = (1, 4)
        lcd.write_string(str(int(self.windkm)))
        lcd.write_string('km/h')
        time.sleep(3)
        lcd.clear()

    def next_tile(self):
        self.counter -= 1
        self.codeIR = pylirc.nextcode()
        if  not self.codeIR or self.codeIR[0] == self.next: 
            if self.next != 4:
                self.next += 1
            else:
                self.next -= 3
        else:
            self.next = int(self.codeIR[0])

email = mail()
weather = weather()
weather.update()
def up_next():
    weather.update()
    weather.next_tile()

while True:
    try:
        while weather.next == 1:
            weather.display_weather()
            up_next()

        while weather.next == 2:
            weather.display_temp()
            up_next()

        while weather.next == 3:
            weather.display_hum()
            up_next()

        while weather.next == 4:
            weather.display_wind()
            email.check()
            up_next()

    except(KeyboardInterrupt, SystemExit):
        print 'quitting'
        lcd.close(clear=True)
        exit()

再看一看。异步/等待语法和使用lirc的非阻塞编程。