Python while loop with invalid syntax

一名 Python 初学者正在开发一个 Python 脚本，用于监控地下室集水池抽水泵中的浮标开关。该脚本需要满足两个条件来检查抽水泵是否不工作：

1. 开关持续打开超过 3 分钟。
2. 开关在 3 分钟内打开和关闭超过 10 次。

目前，该项目仍在开发中，代码如下所示：

import time
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(17, GPIO.IN)
floatSwitch = GPIO.input(17)

import smtplib

running = True
log = open("sumpPumpLog.txt", "r+")
startTime = time.time()


def elapsedTime():
    """This function checks how much time
    has elapsed since the timer has started"""
    endtime = time.time()
    elapsed = endtime - starttime
    return elapsed


def sendEmail(*msg):
    """This function sends an email to selected recipients with a custom
    message as well as the log file attached."""
    #enter the code that sends an email to the family with the log attached

    fromaddr = 'from@email.com'
    toaddrs = [to@email.com']
    msg = """Please see the Pi and the data log file for more details."""

    # Credentials (if needed)
    username = 'my_username'
    password = 'my_password'

    msg.attached()

    # The actual mail send
    server = smtplib.SMTP('smtp.gmail.com:587')
    server.starttls()
    server.login(username, password)
    server.sendmail(fromaddr, toaddrs, msg)
    server.quit()


if running is True:
    if floatSwitch is True:
        #Write the time and what happened to the file
        log.write(str(time.time() + "Float switch turned on")
        #Wait until switch is turned off

        while floatSwitch is True:
            startTime = time.time()
            if floatSwitch is False:
                log.write(str(now) + "Float switch turned off")
                break
        #if elapsedTime > 3 min (in the form of 180 seconds)
        elif elapsedTime() > 180:
            log.write(str(now) + "Sump Pump has been deemed broaken")
            sendEmail("The sump pump is now broken.")

else:
    log.write(str(time.time() + "The sctipt has stopped.")
    sendEmail("The script has been stopped.")

然而，在第 52 行，即 while floatSwitch is True:，出现了一个无效语法的错误。

2. 解决方案

该问题的解决方案有两个方面：

1. 修复无效语法

   第 52 行的错误是缺少一个括号。正确写法应该是：

   while floatSwitch is True:
   

2. 简化代码

   为了使代码更加简洁和易于理解，可以将以下代码替换为：

   while floatSwitch:
   

   这相当于 while floatSwitch is True，因为 floatSwitch 本身就是一个布尔值。

因此，最终修复后的代码为：

import time
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(17, GPIO.IN)
floatSwitch = GPIO.input(17)

import smtplib

running = True
log = open("sumpPumpLog.txt", "r+")
startTime = time.time()


def elapsedTime():
    """This function checks how much time
    has elapsed since the timer has started"""
    endtime = time.time()
    elapsed = endtime - starttime
    return elapsed


def sendEmail(*msg):
    """This function sends an email to selected recipients with a custom
    message as well as the log file attached."""
    #enter the code that sends an email to the family with the log attached

    fromaddr = 'from@email.com'
    toaddrs = [to@email.com']
    msg = """Please see the Pi and the data log file for more details."""

    # Credentials (if needed)
    username = 'my_username'
    password = 'my_password'

    msg.attached()

    # The actual mail send
    server = smtplib.SMTP('smtp.gmail.com:587')
    server.starttls()
    server.login(username, password)
    server.sendmail(fromaddr, toaddrs, msg)
    server.quit()


if running is True:
    if floatSwitch:
        #Write the time and what happened to the file
        log.write(str(time.time() + "Float switch turned on")

        while floatSwitch:
            startTime = time.time()
            if not floatSwitch:
                log.write(str(now) + "Float switch turned off")
                break
        #if elapsedTime > 3 min (in the form of 180 seconds)
        elif elapsedTime() > 180:
            log.write(str(now) + "Sump Pump has been deemed broaken")
            sendEmail("The sump pump is now broken.")

else:
    log.write(str(time.time() + "The sctipt has stopped.")
    sendEmail("The script has been stopped.")