'instancemethod'对象没有带有类变量的属性'__getitem__'

时间:2014-01-26 15:47:45

标签: python raspberry-pi

我正在尝试使用我的Raspberry Pi创建一个python类来控制步进电机。它主要起作用,但每当我将列表定义为类变量时,我继续得到“'instancemethod'对象没有属性'__getitem__'错误。错误消息列出这段代码作为罪魁祸首但是我不能如果seq [self.StepCounter] [pin]!= 0:它看起来有什么问题。如果我将它定义为实例变量或全局变量,它将起作用。 这是我的代码:     将RPi.GPIO导入为GPIO     进口时间     debug = True

class stepper:
    clockwise = []
    clockwise = range(0,4)
    clockwise[0] = [1,0,0,0]
    clockwise[1] = [0,1,0,0]
    clockwise[2] = [0,0,1,0]
    clockwise[3] = [0,0,0,1]
    def __init__(self,pin1,pin2,pin3,pin4):
        GPIO.setwarnings(False)
        GPIO.setmode(GPIO.BCM)
        self.pin1 = pin1
        self.pin2 = pin2
        self.pin3 = pin3
        self.pin4 = pin4
        self.StepCounter = 0
        self.pinarray = [pin1,pin2,pin3,pin4]
        for pin in self.pinarray:
            if debug == True:
                print "Setup pin " + str(pin)
            GPIO.setup(pin,GPIO.OUT)
            GPIO.output(pin, False)
        self.stepNum = 512.0
        self.coilNum = 4.0

    def setup(self,stepNum,coilNum):
        self.stepNum = float(stepNum)
        self.coilNum = float(coilNum)
        self.partNum = self.coilNum * self.stepNum

    def clockwise(self,speed):
        seq = stepper.clockwise
        self.WaitTime = (1.0 / (self.stepNum * self.coilNum)) * speed
        for pin in range(0, 4):
            xpin = self.pinarray[pin]
            if seq[self.StepCounter][pin]!=0:
              GPIO.output(xpin, True)
            else:
              GPIO.output(xpin, False)
        self.StepCounter += 1
        if (self.StepCounter==len(seq)):
            self.StepCounter = 0
        if (self.StepCounter<0):
            self.StepCounter = len(seq)
        time.sleep(self.WaitTime)

print "Adding Motor Instance"    
motor = stepper(24,25,8,7)
print "Spinning Motor"
while "True":
    motor.clockwise(5)

请有人告诉我它有什么问题并解释原因。谢谢

1 个答案:

答案 0 :(得分:11)

你没有发布完整的追溯,但我可以猜一下:

def clockwise(self,speed):
    seq = stepper.clockwise
    self.WaitTime = (1.0 / (self.stepNum * self.coilNum)) * speed
    for pin in range(0, 4):
        xpin = self.pinarray[pin]
        if seq[self.StepCounter][pin]!=0:

您将seq设置为等于第一行上的方法stepper.clockwise。然后几行后你尝试索引它:seq[self.StepCounter]。但是获取方法的self.StepCounter - 元素是什么意思?

没什么,因为:

'instancemethod' object has no attribute '__getitem__'

您不应将clockwise用作列表名称和方法名称;只有最后执行的定义才会成立,所以当你到达seq = stepper.clockwise时,它就是方法,而不是列表。