def NextNumber():
    count = 0
    x = 0
    y = 1
    while count <= int(Range.get()):
        for item in [x]:
            listbox.insert(0, item)
        z = x
        x = z + y
        y = z
        count = count + 1

root = Tk()
Title = Label(root, text = "Calculate fib number:")
Title.pack()
Range = Entry(root)
Range.pack()
PrintNextNumber = Button(root, text = "   Display   ", command = NextNumber)
PrintNextNumber.pack()
listbox = Listbox(root)
listbox.config(selectborderwidth=1, height=1, width=50)
listbox.pack()
root.mainloop()

def fib_nums_1() #defining the function
    count = 0 #We set the count variable to 0 as we have not yet done any production of the numbers
    a = 0 #Sets the first variable we require
    b = 1 #Sets the second necessary variable
    print b #We print the first of our numbers
    count = count + 1 #We add one to the count variable as we have processed and printed one fibonacci number
    c = a + b #We set the second number to be printed as the sum of the first two
    print c #Now we print it
    count = count + 1 #We add another one to the count variable

def fib_nums_2() #Now we are defining the second function of our program
    a = c + b
    print a
    count = count + 1
    b = a + c
    print b
    count = count + 1
    c =  b + a
    count = count + 1

fib_nums_1()

while count != 100: #This obviously means that we will keep running the following code until the count variable is at 100, at which point we will have calculated and printed 100 fibonacci numbers
    fib_nums_2()