def opp(c):
    return 'x' if c == 'o' else 'o'
Returns the cell object at the given position in the data object
dataset/ETHPy150Open thomasballinger/curtsies/examples/tictactoeexample.py/opp--crossover with--dataset/ETHPy150Open Widdershin/butterdb/butterdb/butterdb.py/Database.get_cell