BCIgui/Masterarbeit/test.py

try: 
    from Tkinter import *
except ImportError:
    from tkinter import *

def myClick(string):
    myLabel = Label(root, text=string)
    myLabel.pack()

root = Tk()
myButton = Button(root, text="Click me", command=lambda: myClick("test"), bg="blue")



myButton.pack()

root.mainloop()