def A1ToXy(space):
    """Convert user-friendly coordinates (like A1 or B5) to (x, y)
    coordinates (like 0,0 or 1,4)."""
    column = space[0]
    row = space[1:]
      # The ASCII value of 'A' is 65:
    return (ord(column) - 65, int(row) - 1)