is_terminal()
Returns True if the state is terminal (the game has ended), False otherwise.
import pyspiel
game = pyspiel.load_game("tic_tac_toe")
state = game.new_initial_state()
print(state.is_terminal()) # Output: False
game = pyspiel.load_game("matrix_rps")
state = game.new_initial_state()
print(state.is_terminal()) # Output: False
state.apply_actions([1, 1])
print(state.is_terminal()) # Output: True