parameters: (colour)
docstring: Return the opponent colour.
  
      colour -- 'b' or 'w'
  
      Returns 'b' or 'w'.
docstring_summary: Return the opponent colour.
docstring_tokens: Return the opponent colour .
function: def opponent_of(colour):
      """Return the opponent colour.
  
      colour -- 'b' or 'w'
  
      Returns 'b' or 'w'.
  
      """
      try:
          return _opponents[colour]
      except KeyError:
          raise ValueError
function_tokens: def opponent_of ( colour ) : try : return _opponents [ colour ] except KeyError : raise ValueError