如何将arduino代码翻译成python pyfirmata？

我想用pyfirmata将这个Arduino代码翻译成python代码。我该怎么做

int sw = 0;

void setup() {
  // put your setup code here, to run once:
  pinMode(2, INPUT);
  pinMode(6, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
  sw = digitalRead(2);

  if (sw == LOW){
    digitalWrite(6, LOW);
  }
  else {
    digitalWrite(6, HIGH);
  }
}

我试过了

from pyfirmata import Arduino, util

board = Arduino('COM3')
it = util.Iterator(board)
it.start()

button = board.get_pin('d:2:i')
led = board.get_pin('d:6:o')

while True:
    sw = button.read()
    print(sw)
    if sw:
        led.write(1)
    else:
        led.write(0)

但这不起作用，当我打印

sw

时，它返回

None

然后我试着这样做，但总是返回

None

from pyfirmata import Arduino, util, INPUT

board = Arduino('COM3')
it = util.Iterator(board)
it.start()

while True:
    board.digital[2].mode = INPUT
    board.digital[2].enable_reporting()
    print(board.digital[2].read())