Question

我正在使用python脚本控制树莓派上的一些GPIO引脚。如下：

from gpiozero import PWMLED
import time
import os
from decimal import Decimal

led = PWMLED("GPIO12")              #set the GPIO pin number you are using here. It uses the GPIO method of numbering.
                        #details on pin numbering can be found here: https://gpiozero.readthedocs.io/en/stable/recipes.html
setZero=open("/var/www/html/alpha.txt", "w")
setZero.write("0")
file.close()

while True:                 #a loop that never stops running
    try:                    #prevents an bug with the code that would cause it to terminate when writing to alpha.txt file
        initial=open("/var/www/html/alpha.txt", "r")    #open the alpha.txt file as read only. Declare it as "initial"
        brightness=(initial.read()) #declare the variable brightness by reading the variable "initial". Convert the string into a number
        x = Decimal(brightness)     #convert the number into a decimal. Store it as the variable X
        int_brightness = round(x,2) #round the variable x to 2 decimal places. PHP should handle this, but just in-case. Store the rounded variable as int_brightness
        led.value = int_brightness  #set the brightness of the LED to the value of int_brightnesss
    except:
        ()              #return nothing if code fails
    finally:
        ()              #return nothing if code fails

问题出在以下几行：

setZero=open("/var/www/html/alpha.txt", "w")
setZero.write("0")
file.close()

如果我在没有这三行的情况下运行脚本，则代码可以正常工作。添加后，LED就会停止点亮（我假设while真循环未执行）。我已经确认启动时脚本会成功将0写入文件。

关于什么可能导致此操作失败的任何想法？控制台中没有返回的输出

在Python3中执行true循环时，file.write停止

0 个答案: