variable referenced before assignment.

[d3zz]

Hello. i have this problem with a program im coding in python. heres the code:

#! /usr/bin/python
from Tkinter import *
list=[".", ".", ".", ".", ".", ".", ".", ".", "."]
root=Tk()

def p(lol):
      list[0]=1
      lol["text"] = list[0]
def plade():
      
###### ROW=0     

      a1=Button(root, text=list[0], command=p(a1))
      a1.grid(row=0)
      
      a2=Button(root, text=list[1], command=p(a2))
      a2.grid(row=0, column=1)
      

      a3=Button(root, text=list[2], command=p(a3))
      a3.grid(row=0, column=2)
##### ROW=1



plade()
root.mainloop()

and heres the output:

Traceback (most recent call last):
  File "./kryds", line 26, in <module>
    plade()
  File "./kryds", line 13, in plade
    a1=Button(root, text=list[0], command=p(a1))
UnboundLocalError: local variable 'a1' referenced before assignment

Could you guys please help me figure this out, and explain the solution?

[TrustyTony]

Difficult to understand your goal, but here is something running end result of playing with it:

#! /usr/bin/python
from Tkinter import *
from functools import partial

def p(lol):
      buttons[lol]["text"] = 'Hi from %i!' % lol

def plade(root):
    for n in range(0,4):
      buttons[n] = Button(root, text= 'Button%i' % n, command=partial(p, n))
      buttons[n].grid(row=0, column=n)

buttons=["." for _ in range(4)]
root=Tk()
plade(root)
root.mainloop()

[d3zz]

Thank you!