Base Game¶

A collection of base game classes.

Classes:

ExtensiveFormGame
NormalFormGame

class imperfecto.games.game.ExtensiveFormGame(players)[source]¶

Bases: abc.ABC

Abstract class for extensive form games.

In an extensive form game, players have some private information, and are unsure about the true state of the world.

Note

ExtensiveFormGame subclass must have class-level attribute actions, and n_players.

Parameters: players (Sequence[Player]) – The players of the game.

actions¶

The actions of the game (class-level attribute).

Type: enum.EnumMeta

n_players¶

The number of players in the game (class-level attribute).

Type: int

players¶

The players of the game.

Type: Sequence[Player]

n_players: int¶

actions: enum.EnumMeta¶

property players: Sequence[imperfecto.algos.player.Player]¶

The players of the game.

Return type: Sequence[Player]

abstract get_active_player(history)[source]¶

Get the active player of the game at the current decision point.

Parameters: history (Sequence[IntEnum]) – The history of the game.
Return type: Player
Returns: The active player of the game at the current decision point.

abstract is_terminal(history)[source]¶

Check if the game is in a terminal state.

Parameters: history (Sequence[IntEnum]) – The history of the game.
Return type: bool
Returns: True if the game is in a terminal state, False otherwise.

abstract get_payoffs(history)[source]¶

Return the payoff for each player at the current node.

Note

history must be a terminal node.

Parameters: history (Sequence[IntEnum]) – The history of the game.
Return type: Sequence[float]
Returns: The payoffs of the players at the end of the game.

abstract get_infostate(history)[source]¶

Return the infostate (i.e. the information set) of the game.

Parameters: history (Sequence[IntEnum]) – The history of the game.
Return type: str
Returns: A string representation of the infostate of the game.

history_to_str(history)[source]¶

Return a string representation of the history of the game.

Parameters: history (Sequence[IntEnum]) – The history of the game.
Return type: str
Returns: A string representation of the history of the game.

play()[source]¶

Play the game with the current players and their strategies and return the payoffs.

Return type: Tuple[Sequence[IntEnum], Sequence[float]]
Returns: A tuple of the play-out history of the game and the payoffs of the players.

static shorten_history(history_str)[source]¶

Shorten history string. Games with long action names should override this method.

Parameters: history_str (str) – history string to shorten.
Return type: str
Returns: a shortened history string.

class imperfecto.games.game.NormalFormGame(players)[source]¶

Bases: imperfecto.games.game.ExtensiveFormGame, abc.ABC

N-player normal form game.

This class of game is a special form of extensive-form games. A normal form game involves every player making simultaneous moves. Thus, they are unsure about each other’s move.

Parameters: players (Sequence[Player]) – The players of the game.

is_terminal(history)[source]¶

Check if the game is in a terminal state.

Parameters: history (Sequence[IntEnum]) – The history of the game.
Return type: bool
Returns: True if the game is in a terminal state, False otherwise.

get_infostate(history)[source]¶

Return the infostate (i.e. the information set) of the game.

Parameters: history (Sequence[IntEnum]) – The history of the game.
Return type: str
Returns: A string representation of the infostate of the game.

get_active_player(history)[source]¶

Get the active player of the game at the current decision point.

Parameters: history (Sequence[IntEnum]) – The history of the game.
Return type: Player
Returns: The active player of the game at the current decision point.