from tkinter import Tk, Label, Button
from tkinter.filedialog import askopenfilename

class MyFirstGUI:
    def __init__(self, master):
        self.master = master
        master.title("A simple GUI")

        self.label = Label(master, text="This is our first GUI!")
        self.label.pack()

        self.greet_button = Button(master, text="Greet", command=self.greet)
        self.greet_button.pack()

        self.open_button = Button(master, text="File Path", command = self.open)

        self.close_button = Button(master, text="Close", command=master.quit)
        self.close_button.pack()

    def greet(self):
        print("Greetings!")

    def open(self):
        Tk().withdraw() # we don't want a full GUI, so keep the root window from appearing
        filename = askopenfilename() # show an "Open" dialog box and return the path to the selected file
        print(filename)

root = Tk()
my_gui = MyFirstGUI(root)
root.mainloop()