без достаточного количества информации я делаю некоторые предположения здесь: также я не знаком с tkinter:
вот ссылка для некоторой помощи по передаче параметров вашим функциям с помощью кнопки Как пройтиаргументы команды Button в Tkinter?
from tkinter import filedialog
from tkinter import messagebox
from tkinter import *
master = Tk()
def findFile1():
master.filename = filedialog.askopenfilename(initialdir = "C:/",title = "Select file 1",filetypes = (("CSV","*.csv"),("all files","*.*")))
print (master.filename)
with open(master.filename, 'r') as t1:
fileone = t1.readlines()
return fileone
def findFile2():
master.filename = filedialog.askopenfilename(initialdir = "C:/",title = "Select file 2",filetypes = (("CSV","*.csv"),("all files","*.*")))
print (master.filename)
with open(master.filename, 'r') as t2:
filetwo = t2.readlines()
return filetwo
def saveFile(fileone, filetwo):
master.filename = filedialog.asksaveasfilename(initialdir = "C:/",title = "Save file",filetypes = (("CSV","*.csv"),("all files","*.*")))
print (master.filename)
with open(master.filename, 'w') as outFile:
for line in filetwo:
if line not in fileone:
outFile.write(','.join(line.split()))
messagebox.showinfo("Sucess", "File created successfully!")
file1 = Button(master, text="Load file 1", command=findFile1)
file1.pack()
file2 = Button(master, text="Load file 2", command=findFile2)
file2.pack()
start = Button(master, text="START", command=saveFile)
start.pack()
master.geometry("300x300")
mainloop()