Tkinter 按钮执行脚本抛出 NameError

Question

我有一个带有三个按钮的 Tkinter GUI，每个按钮运行一个单独的脚本。其中两个加载正常，但是第三个抛出一个 NameError，说我的名字之一没有定义。但是，当我不通过 GUI 运行脚本时，它运行良好。

这是图形用户界面代码：

import sys
import os
import tkinter
import cv2
from tkinter.filedialog import askopenfilename
from tkinter import messagebox
import numpy as np 
import matplotlib.pyplot as plt 

top=tkinter.Tk()
top.geometry("300x350")
top.config(background='black')
top.title('Test')
top.resizable(height=False, width=False)

def thresholdCallBack():
    exec(open('motionindexthreshold.py').read())

def autoremoveCallBack():
    exec(open('motionindexgenerator.py').read())

def videoTaggingCallBack():
    exec(open('stepthrough.py').read())

def quitCallBack():
    top.destroy()

M = tkinter.Message(top, text='Test', width=280, background='black', foreground='white', font=('Courier', 28))
B = tkinter.Button(top,text="Define Motion Index Threshold",command= thresholdCallBack)
C = tkinter.Button(top,text="Autoremove Nonmovement Video Segments",command= autoremoveCallBack)
D = tkinter.Button(top,text="Tag Video Frames",command= videoTaggingCallBack)
E = tkinter.Button(top,text="Quit", command=quitCallBack)
B.config(height=5, width=80, background='red')
C.config(height=5, width=80, background='blue', foreground='white')
D.config(height=5, width=80, background='yellow')
E.config(height=5, width=80, background='green')
M.pack()
B.pack()
C.pack()
D.pack()
E.pack()
top.mainloop()

这是注册按键时崩溃的python脚本：

import cv2
import tkinter as tk
from tkinter.filedialog import askopenfilename
from tkinter import messagebox
import numpy as np 
import os
import matplotlib.pyplot as plt 
import sys


framevalues = []
count = 1

root = tk.Tk()
root.withdraw()

selectedvideo = askopenfilename()
selectedvideostring = str(selectedvideo)
cap = cv2.VideoCapture(selectedvideo)
length = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))


def stanceTag():    
    framevalues.append('0' + ' ' + '|' + ' ' + str(int(cap.get(1))))
    print (str(int(cap.get(1))), '/', length) 
    print(framevalues)

def swingTag():
    framevalues.append('1' + ' ' + '|' + ' ' + str(int(cap.get(1))))
    print (str(int(cap.get(1))), '/', length)
    print(framevalues) 

def unsureTag():
    framevalues.append('-1' + ' ' + '|' + ' ' + str(int(cap.get(1))))
    print (str(int(cap.get(1))), '/', length) 
    print(framevalues)

def rewindFrames():
    cap.set(1,((int(cap.get(1)) - 2)))
    print (int(cap.get(1)), '/', length) 
    framevalues.pop()
    print(framevalues)  



while (cap.isOpened()): 
    ret, frame = cap.read()

    # check if read frame was successful
    if ret == False:
            break
    # show frame first
    cv2.imshow('frame',frame)

    # then waitKey
    frameclick = cv2.waitKey(0) & 0xFF

    if frameclick == ord('a'):
        swingTag()

    elif frameclick == ord('r'):
        rewindFrames()

    elif frameclick == ord('s'):
        stanceTag()

    elif frameclick == ord('d'):
        unsureTag()

    elif frameclick == ord('q'):
        with open((selectedvideostring + '.txt'), 'w') as textfile:
            for item in framevalues:
                textfile.write("{}\n".format(item))
        break

    else:
        continue

cap.release()
cv2.destroyAllWindows()

有人知道如何解决这个问题吗？

谢谢

Answer 1

如果您需要从另一个 python 脚本运行代码，那么您应该使用导入来获取另一个脚本并在另一个脚本中运行一个函数。这将是您的代码的问题，因为您的程序核心位于函数之外，因此它会在导入后立即运行。出于（和其他）原因，您应该将所有代码放在函数中。您可以通过检查__main__ 属性来检测代码是否已导入。

我重组了您的代码以将所有代码移动到函数中，然后导入它并从 GUI 按钮调用适当的函数。

这就是您的 GUI 代码的样子：

import tkinter

import motionindexthreshold
import motionindexgenerator
import stepthrough

def main():
    top=tkinter.Tk()
    top.geometry("300x350")
    top.config(background='black')
    top.title('Test')
    top.resizable(height=False, width=False)

    M = tkinter.Message(top, text='Test', width=280, background='black', foreground='white', font=('Courier', 28))
    B = tkinter.Button(top,text="Define Motion Index Threshold",command=motionindexthreshold.main)
    C = tkinter.Button(top,text="Autoremove Nonmovement Video Segments",command=motionindexgenerator.main)
    D = tkinter.Button(top,text="Tag Video Frames",command=stepthrough.main)
    E = tkinter.Button(top,text="Quit", command=top.destroy)
    B.config(height=5, width=80, background='red')
    C.config(height=5, width=80, background='blue', foreground='white')
    D.config(height=5, width=80, background='yellow')
    E.config(height=5, width=80, background='green')
    M.pack()
    B.pack()
    C.pack()
    D.pack()
    E.pack()
    top.mainloop()

if __name__ == '__main__':
    main()

你的模块代码应该是这样的：

import cv2
import tkinter as tk
from tkinter.filedialog import askopenfilename

def stanceTag(cap, framevalues):    
    framevalues.append('0' + ' ' + '|' + ' ' + str(int(cap.get(1))))
    print (str(int(cap.get(1))), '/', length) 
    print(framevalues)

def swingTag(cap, framevalues):
    framevalues.append('1' + ' ' + '|' + ' ' + str(int(cap.get(1))))
    print (str(int(cap.get(1))), '/', length)
    print(framevalues) 

def unsureTag(cap, framevalues):
    framevalues.append('-1' + ' ' + '|' + ' ' + str(int(cap.get(1))))
    print (str(int(cap.get(1))), '/', length) 
    print(framevalues)

def rewindFrames(cap, framevalues):
    cap.set(1,((int(cap.get(1)) - 2)))
    print (int(cap.get(1)), '/', length) 
    framevalues.pop()
    print(framevalues)  


def main():
    framevalues = []
    count = 1

    selectedvideo = askopenfilename()
    selectedvideostring = str(selectedvideo)
    cap = cv2.VideoCapture(selectedvideo)
    length = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))

    while (cap.isOpened()): 
        ret, frame = cap.read()

        # check if read frame was successful
        if ret == False:
                break
        # show frame first
        cv2.imshow('frame',frame)

        # then waitKey
        frameclick = cv2.waitKey(0) & 0xFF

        if frameclick == ord('a'):
            swingTag(cap, framevalues)

        elif frameclick == ord('r'):
            rewindFrames(cap, framevalues)

        elif frameclick == ord('s'):
            stanceTag(cap, framevalues)

        elif frameclick == ord('d'):
            unsureTag(cap, framevalues)

        elif frameclick == ord('q'):
            with open((selectedvideostring + '.txt'), 'w') as textfile:
                for item in framevalues:
                    textfile.write("{}\n".format(item))
            break

        else:
            continue

    cap.release()
    cv2.destroyAllWindows()

if __name__ == '__main__':
    # this is called if this code was not imported ... ie it was directly run
    # if this is called, that means there is no GUI already running, so we need to create a root
    root = tk.Tk()
    root.withdraw()
    main()

显然这是一个猜测；我无法测试这是否可以解决您的问题，但我认为可以。