def calculate_value(player_name, game_data):
    """
    Compute the total ship value of a player.

    Parameters
    ----------
    player_name: name of the player to count value (str)
    game_data: game before command execution (dic)

    Version
    -------
    Specification: Alisson Leist, Bayron Mahy, Nicolas Van Bossuyt (v1. 24/02/17)
    Implementation: Alisson Leist (v1. 24/02/17)
    """
    total_value = 0

    for ship in game_data['ships']:
        if game_data['ships'][ship]['owner'] == player_name:
            total_value += game_data['model_ship'][game_data['ships'][ship]['type']]['price']

    return total_value