list - Python - Random output has a structure -

i writing small script tic tac toe game in python. store tic tac toe grid in list (example of empty grid): [[' ', ' ', ' ',], [' ', ' ', ' ',], [' ', ' ', ' ',]]. these following possible string list:

• ' ' no player has marked field

• 'x' player x

• 'o' player o

i have written function creates empty grid (create_grid), function creates random grid (create_random_grid) (this used testing purposes later) , function prints grid in such manner read-able end user (show_grid). having trouble create_random_grid function, other 2 method work though. here how approached create_random_grid function:

• first create empty grid using create_grid

• iterate on grid line

• iterate on character in line

• change character item randomly selected form here. ['x', 'o', ' ']

• return grid

note: not expect exact output expected output. actual output, not lines same.

i not know why lines same. seems last generated line 1 used. added debug lines in code along examples cleary show problem. added line in code show me randomly chosen mark each slot of grid, output not correspond that, except last line match. have included other important information comments in code. pastebin link here

code:

from random import choice  def create_grid(size=3):     """     size: int. horizontal , vertical height of grid. default set 3 because thats normal     returns: lst. list of lines. lines list of strings         creates empty playing field     """     x_lst = [' '] * size  # horizontal line of code     lst = []  # final list     y in range(size):  # append size times lst proper height         lst.append(x_lst)     return lst  def show_grid(grid):     """     grid: list. list of lines, lines list of string     returns: none     """     line in grid:         print('[' + ']['.join(line)+']')  # print each symbol in box  def create_random_grid(size=3):     """     size: int. horizontal , vertical height of grid. default set 3 because thats normal     returns: lst. list of lines. lines list of strings         creates grid random player marks, used testing purposes     """     grid = create_grid()     symbols = ['x', 'o', ' ']     line in range(size):         column in range(size):             # grid[line][column] = choice(symbols)  # want use, not work              # debug, same version ^^ in smaller steps             random_item = choice(symbols)             print 'line: ', line, 'column: ', column, 'symbol chosen: ', random_item  # shows randomly wirrten mark each slot             grid[line][column] = random_item  # over-write indexes of grid randomly chosen symbol     return grid  hardcoded_grid = [['x', ' ', 'x'], [' ', 'o', 'o'], ['o', 'x', ' ']] grid = create_random_grid() print('\nthe simple list view of random grid:\n'), grid print('\nthis grid created using create_random_grid method:\n') show_grid(grid) print('\nthis grid hard coded (to show show_grid function works):\n') show_grid(hardcoded_grid) 

x_lst = [' '] * size lst = [] y in range(size):     lst.append(x_lst) 

all elements of lst same list object. if want equal independent lists, create new list each time:

lst = [] y in range(size):     lst.append([' '] * size)