>>> row = [""] * 3 #row i['', '', ''] >>> board = [row] * 3 >>> board[0][0] = "X" >>> board [['X', '', ''], ['X', '', ''], ['X', '', '']] I almost felt hel

>>> row = [""] * 3 #row i['', '', ''] >>> board = [row] * 3 >>> board[0][0] = "X" >>> board [['X', '', ''], ['X', '', ''], ['X', '', '']] I almost felt helpless for an hour when I used this list initialization [0] the first time in my code and couldn't find the reason why my unit tests where failing. [0] https://github.com/satwikkansal/wtfpython#-a-tic-tac-toe-where-x-wins-in-the-first-attempt https://github.com/satwikkansal/wtfpython#-a-tic-tac-toe-whe...