Python从外部启停运行中函数：树莓派SenseHat进程重启报错求解

Python multiprocessing.Process 实例为一次性生命周期设计，实例完成运行或被终止后，不允许再次调用 start() 方法启动，这是触发报错的根本原因。

每次需要启动显示逻辑时，重新创建新的 Process 实例即可，同时新增进程运行状态判断，避免重复启动已运行的进程触发异常。
附加优化点：

• 将 SenseHat 实例初始化移入显示函数内部，避免跨进程操作硬件引发偶发故障
• 终止进程后调用 join() 等待资源完全释放，避免产生僵尸进程
• 新增多进程标准入口判断，兼容不同系统的多进程运行规则

from sense_hat import SenseHat
from gpiozero import CPUTemperature
import time
from multiprocessing import Process

def main_display():
    # 把sense初始化放到子进程内部，避免跨进程硬件冲突
    sense = SenseHat()
    w = (50, 50, 50)
    
    display = [
      w, w, w, w, w, w, w, w,
      w, w, w, w, w, w, w, w,
      w, w, w, w, w, w, w, w,
      w, w, w, w, w, w, w, w,
      w, w, w, w, w, w, w, w,
      w, w, w, w, w, w, w, w,
      w, w, w, w, w, w, w, w,
      w, w, w, w, w, w, w, w
      ]
    
    cpu_array = []
    while True:
        # 校准温度
        temp = sense.get_temperature()
        cpu = CPUTemperature()
        cpu_temp = cpu.temperature
        if len(cpu_array) < 100:
            cpu_array.append(cpu_temp)
        else:
            cpu_array.append(cpu_temp)
            cpu_array.pop(0)
        av_cpu_temp = sum(cpu_array) / len(cpu_array)
        temp_calibrated = temp - ((av_cpu_temp - temp) * 1.6)
        
        pres = sense.get_pressure()
        hum = sense.get_humidity()
        # 温度列渲染
        temp_list = [56, 57, 48, 49, 40, 41, 32, 33, 24, 25, 16, 17, 8, 9, 0, 1]
        temp_color = [(0, 0, 255), (20, 0, 235), (40, 0, 215), (70, 0, 185), (100, 0, 155), (120, 0, 135), (140, 0, 115), (160, 0, 95), (170, 0, 85), (180, 0, 75), (190, 0, 65), (200, 0, 55), (210, 0, 45), (220, 0, 35), (230, 0, 25), (255, 0, 0)]
        i = 0
        target_temp = 0
        while i < len(temp_list):
            display[temp_list[i]] = temp_color[i] if temp_calibrated >= target_temp else w
            i += 1
            target_temp += 3
            
        # 气压列渲染
        pres_list = [59, 60, 51, 52, 43, 44, 35, 36, 27, 28, 19, 20, 11, 12, 3, 4]
        pres_color = [(255,255,153), (255, 243, 157), (255,232,162), (255,209,172), (255, 197, 176), (255,185,181), (255,162,190), (255,139,199), (255,116,209), (255,93,218), (255, 81, 222), (255,70,227), (255,46,236), (255,23,246), (255, 11, 250), (255,0,255)]
        j = 0
        target_pres = 930
        while j < len(pres_list):
            display[pres_list[j]] = pres_color[j] if pres >= target_pres else w
            j += 1
            target_pres += 10
            
        # 湿度列渲染
        hum_list = [62, 63, 54, 55, 46, 47, 38, 39, 30, 31, 22, 23, 14, 15, 6, 7]
        hum_color = [(0,255,0), (0, 243, 11), (0,232,23), (0,209,46), (0,185,70), (0,162,93), (0, 150, 104), (0,139,116), (0,116,139), (0,93,162), (0, 81, 173), (0,70,185), (0,46,209), (0,23,232), (0, 11, 244), (0,0,255)]
        k = 0
        target_hum = 0
        while k < len(hum_list):
            display[hum_list[k]] = hum_color[k] if hum >= target_hum else w
            k += 1
            target_hum += 6.25
            
        sense.set_pixels(display)
        time.sleep(1)
        
if __name__ == "__main__":
    # 主进程保留sense实例用于摇杆检测
    sense = SenseHat()
    current_process = None
    # 启动时默认运行显示
    current_process = Process(target=main_display)
    current_process.start()
    
    while True:
        for event in sense.stick.get_events():
            if event.action == "pressed":
                if event.direction == "up":
                    # 仅无运行中进程时启动新进程
                    if current_process is None or not current_process.is_alive():
                        current_process = Process(target=main_display)
                        current_process.start()
                elif event.direction == "down":
                    # 仅存在运行中进程时执行终止
                    if current_process is not None and current_process.is_alive():
                        current_process.terminate()
                        current_process.join()
                        current_process = None
                        sense.clear()
        time.sleep(0.1)

内容的提问来源于stack exchange，提问作者Wallaby3