Python 如何在超时的情况下从GPIO读取输入

我目前正在构建一个分支菜单系统，它使用3个按钮来选择左、右、选择。使用python，我如何读取这些按钮的输入，以便在用户不按按钮15秒的情况下返回主菜单？

我想我能够使用以下代码包含超时，该代码使用树数据结构来实现菜单

##Create a class for storing menu items within a tree
class menu_tree:
    'This class stores menu options'

    #Create an initalization function for root node
    def __init__(self, option):
        self.option = option #initialize option value
        self.children = [] #intialize empty child list
        self.parent = None #root has no parents (Aww D: )

    #Create a function for adding child nodes
    def add_child(self, child):
        child.parent = self #parent of new instance becomes old instance
        self.children.append(child) #add child instance to list of children

#Begin creation of menu menu tree
root = menu_tree("Main Menu") #Create root node for main menu

Light = menu_tree("Light") #Create child node for light
Light.add_child(menu_tree("Hours")) #Add child node for amount of hours to light
Light.add_child(menu_tree("Time")) #Add child node for time of day to start lighting

root.add_child(Light) #Add child node for light
root.add_child(menu_tree("Water")) #Add a child node for water
root.add_child(menu_tree("Soil")) #Add a child node for soil
root.add_child(menu_tree("Temp")) #Add a child node for temp
root.add_child(menu_tree("Humidity")) #Add a child node for humidity

#Create a function for choosing between menu options
def menu():

    current_option = root.option #Set initial option to the root option
    position = 0 #set left/right postion
    timer = 0 #start timer

    while timer <= 80: #infinite loop while user is actively choosing
        oled.write_center(current_option.children[position]) #print the current option to the screen

        if pi.read(BUTTON_ONE) == True :
            if postion != 0: #can't have negative postion
                position -= 1 #move one spot to the left
            else:
                position = len(current_option.children)
                timer = 0 #reset timer
        elif pi.read(BUTTON_TWO) == True :
            if len(current_option.children) != 0: #if current option has children
                current_option = current_option.children[position] #set the current option to the first child of the chosen node
                timer = 0 #reset timer
            else: #if the option has no children, it is the final option
                return current_option.option #and it's string is returned
        elif pi.read(BUTTON_THREE) == True:
            if postion < len(current_option.children): #if position is not at the end of the list
                position += 1 #move one spot to the right
            else:
                position = 0 #move position back to other end
            timer = 0 #reset timer
        else:
            timer += 1 #count the timer up

        time.sleep(0.25) #1/4 second delay

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我想我能够使用下面的代码包含超时，它使用树数据结构来实现菜单

##Create a class for storing menu items within a tree
class menu_tree:
    'This class stores menu options'

    #Create an initalization function for root node
    def __init__(self, option):
        self.option = option #initialize option value
        self.children = [] #intialize empty child list
        self.parent = None #root has no parents (Aww D: )

    #Create a function for adding child nodes
    def add_child(self, child):
        child.parent = self #parent of new instance becomes old instance
        self.children.append(child) #add child instance to list of children

#Begin creation of menu menu tree
root = menu_tree("Main Menu") #Create root node for main menu

Light = menu_tree("Light") #Create child node for light
Light.add_child(menu_tree("Hours")) #Add child node for amount of hours to light
Light.add_child(menu_tree("Time")) #Add child node for time of day to start lighting

root.add_child(Light) #Add child node for light
root.add_child(menu_tree("Water")) #Add a child node for water
root.add_child(menu_tree("Soil")) #Add a child node for soil
root.add_child(menu_tree("Temp")) #Add a child node for temp
root.add_child(menu_tree("Humidity")) #Add a child node for humidity

#Create a function for choosing between menu options
def menu():

    current_option = root.option #Set initial option to the root option
    position = 0 #set left/right postion
    timer = 0 #start timer

    while timer <= 80: #infinite loop while user is actively choosing
        oled.write_center(current_option.children[position]) #print the current option to the screen

        if pi.read(BUTTON_ONE) == True :
            if postion != 0: #can't have negative postion
                position -= 1 #move one spot to the left
            else:
                position = len(current_option.children)
                timer = 0 #reset timer
        elif pi.read(BUTTON_TWO) == True :
            if len(current_option.children) != 0: #if current option has children
                current_option = current_option.children[position] #set the current option to the first child of the chosen node
                timer = 0 #reset timer
            else: #if the option has no children, it is the final option
                return current_option.option #and it's string is returned
        elif pi.read(BUTTON_THREE) == True:
            if postion < len(current_option.children): #if position is not at the end of the list
                position += 1 #move one spot to the right
            else:
                position = 0 #move position back to other end
            timer = 0 #reset timer
        else:
            timer += 1 #count the timer up

        time.sleep(0.25) #1/4 second delay