我在将一个变量从一个类函数传递给Python中的另一个类函数时遇到了麻烦

Question

我是Python的新手，我可能过于复杂了。我没有使用类就可以工作，但我正在尽可能多地学习Python。我正在尝试从同一个类中的另一个函数中的一个函数访问变量。我的代码将在PyCharm控制台中显示各种项目，如何将这些项目放入我的GUI？这是我的整个代码：

# Python version 3.5.1
# pyVISA version 1.8
# Collect measurement data from an Agilent U2001A USB Power Sensor

from tkinter import *  # tkinter is for setting up a GUI
from tkinter import ttk
import visa  # Import the Python VISA module


class agilentU2001A(Frame):

    def __init__(self, master):  # Initialize the frame
        Frame.__init__(self, master)
        rm = visa.ResourceManager()
        ports = rm.list_resources()
        self.sensor = rm.open_resource(ports[0])
        print(self.sensor)
        self.grid()
        self.sensorID()
        self.createWidgets()

    def createWidgets(self):  # Create the labels and buttons
        # Create connected instrument labels
        self.label1 = Label(self, text="Connected sensor: ")
        self.label1.grid(row=0, column=0, sticky=E)
        self.instrumentLabel = Label(self, text="sensor_name")
        self.instrumentLabel.grid(row=0, column=1, sticky=W)

        # Create measurement labels
        self.label2 = Label(self, text="Measurement: ")
        self.label2.grid(row=1, column=0, sticky=E, pady=10)
        self.measurementLabel = Label(self, text="numbers")
        self.measurementLabel.grid(row=1, column=1, sticky=W, pady=10)

        # Create measurement button
        self.measureButton = ttk.Button(self, text="Take Measurement!", command=self.measurement)
        self.measureButton.grid(row=2, column=1, pady=25)

        # Create exit button
        self.exitButton = ttk.Button(self, text="Exit", command=self.exit_measurement)
        self.exitButton.grid(row=2, column=2, padx=25, pady=25)

    def sensorID(self):  # Get the ID from the connected sensor
        self.sensor.write("*IDN?")  # Query the instrument ID
        sensor_init = self.sensor.read()
        print("Sensor ID -> " + sensor_init)

    def exit_measurement(self):  # Close the VISA connection and program
        self.sensor.close()  # Close the connection
        sys.exit()

    def measurement(self):  # Take a measurement
        self.sensor.write("INIT:CONT ON")  # Initiate the trigger to continuous on
        self.sensor.write("FETC?")  # Read data using the fetch command
        measure = self.sensor.read()
        print(measure)

root = Tk()
root.title("Agilent U2001A USB Power Sensor")

app = agilentU2001A(root)

w = 485  # set width of window
h = 180  # set height of window
ws = root.winfo_screenwidth()  # get current screen width
hs = root.winfo_screenheight()  # get current screen height
x = (ws / 2) - (w / 2)  # calculate x coordinate for window
y = (hs / 2) - (h / 2)  # calculate y coordinate for window

root.geometry("%dx%d+%d+%d" % (w, h, x, y))  # center window on screen

root.mainloop()  # Constantly checks for input