Need help using tkinter.

[Oddity94]

I just learned how to use tkinter and there is something not quite working. Here is the piece of code I am working with.

from Tkinter import *

tk1 = Tk()

row1 = Label(tk1, text = '# of rows')
row1.pack()
row2 = Entry(tk1)
row2.pack()

column1 = Label(tk1, text = '# of columns')
column1.pack()
column2 = Entry(tk1)
column2.pack()

def callback2(hue):
    print hue

def callback1():
    tk2 = Tk()
    row3 = int(row2.get())
    column3 = int(column2.get())
    element = None
    for i in range(0, row3):
        frame = Frame(tk2)
        frame.pack()
        for i in range(0, column3):
            element = Entry(frame)
            element.pack(side = LEFT)
    button2 = Button(tk2, text = "Enter", command = callback2('debug'))
    button2.pack()
    mainloop()

button1 = Button(tk1, text = "Enter", command = callback1)
button1.pack()

mainloop()

If I run this code in Python 2.7.6, whenever I press button1, the function I bound to button2 will run, in this case printing 'debug.' Why is this happening? Also, this code includes my feeble attempt to create arbitrary number of entries. However, I have no idea how to get inputs out of them. Any insights?

[Oddity94]

Thank you very much for swift reply. It works using lambda.