Python TkInter按钮命令返回

Question

I'm having trouble returning a variable from a TkInter button command. This here is my code:

class trip_calculator:

    def gui(self):

        returned_values = {} 

        def open_file_dialog():
            returned_values['filename'] = askopenfilename()

        root = Tk()
        Button(root, text='Browse', command= open_file_dialog).pack()

        filepath = returned_values.get('filename')

        root.mainloop()

        return filepath

        root.quit()

I just want to return the filepath of a TXT file. The TkInter window is open and I can browse and choose the file but it then doesn't return the path. I'm going nuts!

    def __init__(self):

        file = self.gui()

Any ideas? Thanks a bunch!

Answer 1

The way your code is now, filepath is assigned its value before your window even appears to the user. So there's no way the dictionary could contain the filename that the user eventually selects. The easiest fix is to put filepath = returned_values.get('filename') after mainloop , so it won't be assigned until mainloop ends when the user closes the window.

from Tkinter import *
from tkFileDialog import *

class trip_calculator:

    def gui(self):

        returned_values = {} 

        def open_file_dialog():
            returned_values['filename'] = askopenfilename()

        root = Tk()
        Button(root, text='Browse', command= open_file_dialog).pack()


        root.mainloop()

        filepath = returned_values.get('filename')
        return filepath

        root.quit()

print(trip_calculator().gui())