How to copy to clipboard in Tkinter with button?

I'm developing a Python/Tkinter program to generate random numbers.

def ButClick():
try:
MinNum = int (txt1.get())
MaxNum = int (txt2.get())
Num = int (txt3.get())
except ValueError:
messagebox.showerror("ValueError", "Check if you typed in correct! You can't type in text! Numbers only!")
else:
Nums = ''
if MinNum <= MaxNum: 
last = MinNum - 1  
i = 0
while i < Num:
numOne = randint(MinNum,MaxNum)
if numOne != last:
Nums = Nums + " " + str(numOne)
i += 1              
last = numOne
scr.config(state="normal")  
scr.insert(INSERT, str(Nums) + "\n")
scr.see("end")
scr.config(state="disabled") 
else:
messagebox.showerror("NumError!", "Your Min Number can't be higher than your Max Number or vice versa!")
def copy(scr):
root.clipboard_get(scr)
root.clipboard_append(scr)
def remove_text():
scr.config(state="normal")
scr.delete(1.0,END)
scr.config(state="disabled")
def confirm():
answer = askyesno(title='Exit',
message='Tired of randomness?')
if answer:
root.destroy() 
root = Tk()
root.title("Hey")
message = Label(root, text= "Welcome to random numbers generator! Developed by Yaroslav Poremsky")
message.pack()
root = Tk()
root.title("Random is so random :)")
# Створення кнопок та текстових полів 
lb1 = Label(root, bg = "green", text = "Min number") 
lb1.grid(
row = 0, 
column = 0,
pady = 10, 
padx = 10) 
txt1 = Entry(root, width = 30)  
txt1.grid(
row = 0,
column = 1,
pady = 10,
padx = 10)
lb2 = Label(root, bg = "orange", text = "Max number")
lb2.grid(
row = 1,
column = 0,
pady = 10,
padx = 10)
txt2 = Entry(root, width = 30)
txt2.grid(
row = 1,
column = 1,
pady = 10,
padx = 10)
lb3 = Label(root,  bg = "pink", text = "Number")
lb3.grid(
row = 2,
column = 0,
pady = 10,
padx = 10)
txt3 = Entry(root, width = 30)
txt3.grid(
row = 2,
column = 1,
pady = 10,
padx = 10)
but = Button(root, width = 15, height = 2,  bg = "magenta", text = "Generate", command = ButClick) 
but.grid(
row = 3,
column = 0,
columnspan = 2, # кількість суміжних стовпців, які може охоплювати кнопка
pady = 10,
padx = 10)
but_remove = Button(root, width = 15, height = 2, bg = "crimson", text = "Remove", command = remove_text) 
but_remove.grid(
row = 3,
column = 1,
columnspan = 2,
pady = 15,
padx = 20)
but_quit = Button(root, width = 15, height = 2, bg = "violet", text = "Quit", command = confirm) 
but_quit.grid(
row = 3,
column = 3,
columnspan = 2,
pady = 15,
padx = 20)
but_copy = Button(root, width = 15, height = 2, bg = "violet", text = "Copy", command = copy)
but_copy.grid(
row = 4,
column = 3,
columnspan = 2,
pady = 15,
padx = 20)
scr = scrolledtext.ScrolledText(root, bg = "grey", height = 10, state="disable") 
scr.grid(
row = 4,
column = 0,
columnspan = 2,
pady = 10,
padx = 10)
root.mainloop()

I implemented a "Copy" button to copy to clipboard all the randomly generated numbers in the text box(scr). The Problem is, my def copy function returns an error:

  return self.func(*args)
TypeError: copy() missing 1 required positional argument: 'scr'

What can be the problem?

Your copy function takes as argument the text to be appended to the clipboard, but when pressing the button, you are not passing any input to the function (buttons assume input is given implicitly to their function).

Instead what you can do, is change your copy function to have no arguments, and read the value of your ScrolledText widget directly in the function body, like so:

def copy():
root.clipboard_append(scr.get(1.0, END))