第32行Typeerror：_ _ 96 _ _不支持的类型：'function'int

Question

系统检查总是说没有问题，但是当我将其上传到我的微型机时，这就是我的代码

from microbit import *
import time

def forward():
    pin13.write_digital(1) 
    pin14.write_digital(1)  
    pin15.write_digital(0)  
    pin16.write_digital(1)  

def backward():
    pin13.write_digital(0)  
    pin14.write_digital(1)  
    pin15.write_digital(1)  
    pin16.write_digital(1)  


def left():
    pin13.write_digital(1) 
    pin14.write_digital(1)  
    pin15.write_digital(0)  
    pin16.write_digital(0)  

def right():
    pin13.write_digital(1)  
    pin14.write_digital(0)  
    pin15.write_digital(0)  
    pin16.write_digital(1) 

while True:
    if left >= 500 and right >= 500:
        forward()
        time.sleep_ms(1500)
    elif left <= 500 and right <= 500:
        right()
        time.sleep_ms(1500)
    elif left <= 500 and right <= 500:
        left()
        time.sleep_ms(1500)

问题 如果左侧> = 500，右侧> = 500：