错误：引发portNotOpenError serial.serialutil.SerialException：尝试使用未打开的端口

Question

我正在尝试绘制温度和湿度的实时图表。我已经为此使用了dht22（am2302）传感器和arduino。
这是我的代码：

import sys, serial, argparse
import numpy as np
from time import sleep
from collections import deque

import matplotlib.pyplot as plt 
import matplotlib.animation as animation


# plot class
class AnalogPlot:
  # constr
  def __init__(self, strPort, maxLen):
      # open serial port
      self.ser = serial.Serial(strPort, 9600)
      self.ser.isOpen()
      self.ax = deque([0.0]*maxLen)
      self.ay = deque([0.0]*maxLen)
      self.maxLen = maxLen

  # add to buffer
  def addToBuf(self, buf, val):
      if len(buf) < self.maxLen:
          buf.append(val)
      else:
          buf.pop()
          buf.appendleft(val)

  # add data
  def add(self, data):
      assert(len(data) == 2)
      self.addToBuf(self.ax, data[0])
      self.addToBuf(self.ay, data[1])

  # update plot
  def update(self, frameNum, a0, a1):
      try:
          line = self.ser.readline()
          data = [float(val) for val in line.split()]
          # print data
          if(len(data) == 2):
              self.add(data)
              a0.set_data(range(self.maxLen), self.ax)
              a1.set_data(range(self.maxLen), self.ay)
      except KeyboardInterrupt:
          print('exiting')

      return a0, 

  # clean up
  def close(self):
      # close serial
      self.ser.flush()
      self.ser.close()    

# main() function
def main():
  # create parser
  parser = argparse.ArgumentParser(description="LDR serial")
  # add expected arguments
  parser.add_argument('--port',dest='port')

  # parse args
  args = parser.parse_args()

  #strPort = '/dev/tty.usbserial-A7006Yqh'
  strPort = args.port
  print(args.port)
  print('reading from serial port %s...' % strPort)

  # plot parameters
  analogPlot = AnalogPlot(strPort, 100)

  print('plotting data...')

  # set up animation
  fig = plt.figure()
  ax = plt.axes(xlim=(0, 100), ylim=(0, 1023))
  a0, = ax.plot([], [])
  a1, = ax.plot([], [])
  anim = animation.FuncAnimation(fig, analogPlot.update, 
                                 fargs=(a0, a1), 
                                 interval=50)

 # show plot
  plt.show()
 # clean up
  analogPlot.close()

  print('exiting.')

# call main
if __name__ == '__main__':
  main()

请帮助我解决此错误并准确绘制实时图形。 这是数字窗口：

该图未显示任何数据。我想绘制实时数据。

Answer 1

更改以下内容

parser.add_arguement('--port', dest='port', required=True)

到

parser.add_arguement('--port', dest='port')

否则您需要在运行脚本时传递端口

python second.py --port <port name>