chess_moves / engine.py
hash-map's picture
Update engine.py
ed3b156 verified
"""
this file contains all details of game state and other parametrs
"""
class GameState():
def __init__(self,board=[[]]):
self.board=[['bR','bN','bB','bQ','bK','bB','bN','bR'],
['bp','bp','bp','bp','bp','bp','bp','bp'],
['--','--','--','--','--','--','--','--'],
['--','--','--','--','--','--','--','--'],
['--','--','--','--','--','--','--','--'],
['--','--','--','--','--','--','--','--'],
['wp','wp','wp','wp','wp','wp','wp','wp'],
['wR','wN','wB','wQ','wK','wB','wN','wR']
]
if self.is_valid_board(board):
self.board=board
self.whiteToMove=True
self.moveLog=[]
self.knight_directions=[(-2, -1), (-1, -2), (-2, 1), (-1, 2), (2, -1), (1, -2), (2, 1), (1, 2)]
self.bishop_directions= [(-1,-1),(-1,1),(1,-1),(1,1)]
self.king_directions=[(-1,0),(0,-1),(1,0),(0,1),(-1,-1),(-1,1),(1,-1),(1,1)]
self.check_mate = False
self.steale_mate = False
self.inheck = False # if king is in check this will be True
self.pins=[] # if any peice stopping the check and if u move them u gona get check
self.checks=[] # possible checks
# we need to keep track of squares where u can eliminate if u took double move in the first place
#that move name is empassant move
# we can have dictionary to store functions
self.protects=[[]]
self.threatens =[[]]
self.peices_can_move_to = [[]]
self.move_functions={'p':self.get_pawn_moves,
'R':self.get_rook_moves,
'N':self.get_knight_moves,
'B':self.get_bishop_moves,
'K':self.get_king_moves,
'Q':self.get_queen_moves
}
#solution 1 to checks is keep track of kings location
self.black_king_location=(0,4)
self.white_king_location=(7,4)
# we need to keep track of squares where u can eliminate if u took double move in the first place
#that move name is empassant move
# we can have dictionary to store functions
self.empassant_moves=() #square for which empassant move is possible
self.current_castling_rights = Castling_Rights(True,True,True,True)
self.castle_rights_log=[Castling_Rights(self.current_castling_rights.wks,self.current_castling_rights.wqs,self.current_castling_rights.bks,self.current_castling_rights.bqs)]
self.empassant_possible_log=[self.empassant_moves]
self.update_state_variables()
# when current castling rights modified it creates new object and pt it in log
'''
To castle, your king and the chosen rook must not have moved,
there must be no pieces between them,
the king cannot be in or pass through check,
and the king must not end up in check.
castle must be first move to both king and rook
this is the only move where two peice move
'''
def make_move(self,move): #this is not for castling and pawn promotion just to add it for squares
self.board[move.start_row][move.start_col]= '--'
self.board[move.end_row][move.end_col]= move.peice_moved
if move.peice_moved=='bK':
self.black_king_location= (move.end_row,move.end_col)
if move.peice_moved=="wK":
self.white_king_location= (move.end_row,move.end_col)
if move.is_pawn_promotion:
self.board[move.end_row][move.end_col] = move.peice_moved[0]+ move.promotion_choice
#castle move
if move.castle:
if move.end_col - move.start_col ==2: #king side col
self.board [move.end_row][move.end_col-1]= self.board[move.end_row][move.end_col+1]
self.board[move.end_row][move.end_col+1]='--'
else:
self.board [move.end_row][move.end_col+1]= self.board[move.end_row][move.end_col-2] #2 squares aqay from it starts
self.board[move.end_row][move.end_col-2]='--'
#empassant move
if move.is_empassant_move: # remove square that is not captured but on the road
self.board[move.start_row][move.end_col] = '--' # capturing the pawn
#update empassant possible
#only in the case
if move.peice_moved[1] == 'p' and abs(move.start_row-move.end_row)==2:
self.empassant_moves=( (move.start_row + move.end_row)//2 ,move.end_col )
else:
self.empassant_moves = ()
#update castling rights whenever is is king or rook moves
self.update_castle_rights(move)
self.castle_rights_log.append(Castling_Rights(self.current_castling_rights.wks,self.current_castling_rights.wqs,self.current_castling_rights.bks,self.current_castling_rights.bqs))
self.empassant_possible_log.append(self.empassant_moves)
self.moveLog.append(move)
self.whiteToMove = not self.whiteToMove #switch turns
'''
undo the previous move made
'''
def undo_move(self):
if len(self.moveLog):
l_move = self.moveLog.pop()
self.whiteToMove = not self.whiteToMove
self.board[l_move.end_row][l_move.end_col]=l_move.peice_captured
self.board[l_move.start_row][l_move.start_col]=l_move.peice_moved
move=l_move
if move.peice_moved=='bK':
self.black_king_location= (move.start_row,move.start_col)
if move.peice_moved=="wK":
self.white_king_location= (move.start_row,move.start_col)
if move.is_empassant_move:
self.board[l_move.end_row][l_move.end_col] = '--' #leave end row and column as it is
self.board[l_move.start_row][l_move.end_col]= move.peice_captured
self.empassant_possible_log.pop()
self.empassant_moves = self.empassant_possible_log[-1]
if move.castle:
if move.end_col - move.start_col ==2: #king side col
self.board [move.end_row][move.end_col+1]= self.board[move.end_row][move.end_col-1]
self.board[move.end_row][move.end_col-1]='--'
else:
self.board [move.end_row][move.end_col-2]= self.board[move.end_row][move.end_col+1] #2 squares aqay from it starts
self.board[move.end_row][move.end_col+1]='--'
## undo the castling rights
self.castle_rights_log.pop() #get rid of new castle rights
self.current_castling_rights = self.castle_rights_log[-1]
#undo checkmate move
self.check_mate = False
self.steale_mate = False
else:
print("this is our starting move ")
#if u move then it might be check to u so need to check these possiblities
#so we need to generate possible moves in next turn abd based on that we need to move
def update_state_variables(self):
# Ensure move log is empty for a fresh board
self.moveLog = []
# Initialize game status flags
self.whiteToMove = True
self.checkmate = False
self.stalemate = False
self.in_check = False
self.pins = []
self.checks = []
self.protects = []
self.threatens = []
self.pieces_can_move_to = []
# Update king locations by scanning the board
self.white_king_location = None
self.black_king_location = None
for row in range(8):
for col in range(8):
if self.board[row][col] == 'wK':
self.white_king_location = (row, col)
if self.board[row][col] == 'bK':
self.black_king_location = (row, col)
# Set default king locations if not found (for standard board)
if not self.white_king_location:
self.white_king_location = (7, 4)
if not self.black_king_location:
self.black_king_location = (0, 4)
# Reset en passant
self.empassant_moves = ()
self.empassant_possible_log = [()]
# Set castling rights based on piece positions
self.current_castling_rights = Castling_Rights(False, False, False, False)
if self.white_king_location == (7, 4):
if self.board[7][0] == 'wR':
self.current_castling_rights.wqs = True
if self.board[7][7] == 'wR':
self.current_castling_rights.wks = True
if self.black_king_location == (0, 4):
if self.board[0][0] == 'bR':
self.current_castling_rights.bqs = True
if self.board[0][7] == 'bR':
self.current_castling_rights.bks = True
self.castle_rights_log = [Castling_Rights(
self.current_castling_rights.wks, self.current_castling_rights.wqs,
self.current_castling_rights.bks, self.current_castling_rights.bqs
)]
# Calculate pins, checks, and in_check
self.incheck,self.pins,self.checks = self.check_for_pins_and_checks()
def is_valid_board(self, board):
if len(board) != 8:
return False
valid_pieces = {'bR', 'bN', 'bB', 'bQ', 'bK', 'bp', 'wR', 'wN', 'wB', 'wQ', 'wK', 'wp', '--'}
white_kings = 0
black_kings = 0
for row in range(8):
if len(board[row]) != 8:
return False
for col in range(8):
cell = board[row][col]
if cell not in valid_pieces:
return False
if cell == 'wK':
white_kings += 1
if cell == 'bK':
black_kings += 1
# No pawns on promotion ranks
if row in (0, 7) and cell[1] == 'p':
return False
if white_kings != 1 or black_kings != 1:
return False
return True
'''
all moves including checks
'''
def update_castle_rights(self,move):
if move.peice_moved=='wK':
self.current_castling_rights.wks=False
self.current_castling_rights.wqs=False
elif move.peice_moved=='bK':
self.current_castling_rights.bks=False
self.current_castling_rights.bqs=False
elif move.peice_moved=='wR' and move.start_row==0:
if move.start_col==7:
self.current_castling_rights.wks=False
elif move.start_col==0:
self.current_castling_rights.wqs=False
elif move.peice_moved=='bR' and move.start_row==7:
if move.start_col==7:
self.current_castling_rights.bks=False
elif move.start_col==0:
self.current_castling_rights.bqs=False
# if rook is captured
if move.peice_captured == 'wR':
if move.end_row == 7:
if move.end_col == 0:
self.current_castling_rights.wqs=False
elif move.end_col == 7:
self.current_castling_rights.wks = False
elif move.peice_captured == 'bR':
if move.end_row == 0:
if move.end_col == 0:
self.current_castling_rights.bqs=False
elif move.end_col == 7:
self.current_castling_rights.bks = False
def is_valid_square(self,r,c):
if r>=0 and r<=7 and c>=0 and c<=7:
return True
else:
return False
def king_safety(self, color):
board = self.board
score = 0
# Find king position
king_pos = None
for r in range(8):
for c in range(8):
if board[r][c] == color + 'K':
king_pos = (r, c)
break
if king_pos:
break
if not king_pos:
return 0 # King missing? shouldn't happen.
r, c = king_pos
# Pawn shield (pawns in front of king)
if color == 'w':
pawn_row = r - 1
if pawn_row >= 0:
for dc in [-1, 0, 1]:
cc = c + dc
if 0 <= cc < 8:
if board[pawn_row][cc] == 'wp':
score += 30 # strong pawn shield
elif board[pawn_row][cc] == '--':
score -= 15 # weak if missing
else: # black
pawn_row = r + 1
if pawn_row < 8:
for dc in [-1, 0, 1]:
cc = c + dc
if 0 <= cc < 8:
if board[pawn_row][cc] == 'bp':
score += 30
elif board[pawn_row][cc] == '--':
score -= 15
# Open file penalty (if no pawn in king’s file)
file_has_pawn = False
for rr in range(8):
if board[rr][c] == color + 'p':
file_has_pawn = True
break
if not file_has_pawn:
score -= 40 # open file in front of king is dangerous
# Enemy attacks around the king (adjacent squares)
king_zone = [(r + dr, c + dc) for dr in [-1, 0, 1] for dc in [-1, 0, 1] if not (dr == 0 and dc == 0)]
enemy_color = 'w' if color == 'b' else 'b'
for (rr, cc) in king_zone:
if 0 <= rr < 8 and 0 <= cc < 8:
self.whiteToMove = not self.whiteToMove
moves = self.get_all_possible_moves()
for move in moves:
if (move.end_row, move.end_col) == (rr, cc):
score -= 20 # enemy attacks near king
self.whiteToMove = not self.whiteToMove
return score
def get_valid_moves(self):
#naive solution
#this is very inefficient and generate all moves in two levels for check
#generate all moves
# for all moves try to generate next possible moves
#for each opponent move check if he can attack your king
#if my king is attacked then it is invalid
# # if u are removing then it is better to traverse list backwards
# #indexes wont shift
# for i in range(len(moves)-1,-1,-1):
# self.make_move(moves[i])
# #swap turns so this will check my check moves
# self.whiteToMove = not self.whiteToMove
# if self.has_check():
# moves.remove(moves[i])
# self.whiteToMove = not self.whiteToMove
# self.undo_move()
# decide algo2
#check for all verticals,horizantals,diagnols and which peices can attack king
#check for kinght attacks
#check for direct checks
#check for if i move this peice can i got any check
#ckeck for check where u have to move
self.incheck,self.pins,self.checks = self.check_for_pins_and_checks()
if self.whiteToMove:
king_row,king_col = self.white_king_location
else:
king_row,king_col = self.black_king_location
if self.incheck:
if len(self.checks)==1:
moves = self.get_all_possible_moves()
check_row,check_col,x_dist,y_dist = self.checks[0]
peice_checking = self.board[check_row][check_col]
valid_squares=[]
if peice_checking[1]=='N':
valid_squares=[(check_row,check_col)]
else:
for i in range(1,8):
valid_square = (king_row + i*x_dist , king_col + i*y_dist)
valid_squares.append(valid_square)
if valid_square[0] == check_row and valid_square[1]==check_col: #once u get to peice and checks
break
for i in range(len(moves)-1,-1,-1):
if moves[i].peice_moved[1] != 'K':
if not ( moves[i].end_row,moves[i].end_col) in valid_squares: #these moves not blobk check so no need
moves.remove(moves[i])
else: # double check king has to move
moves=[]
moves=self.get_king_moves(king_row,king_col,moves)
else:
moves = self.get_all_possible_moves() # no check so all moves are fine
if self.whiteToMove:
self.get_castle_moves(self.white_king_location[0],self.white_king_location[1],moves,'w')
else:
self.get_castle_moves(self.black_king_location[0],self.black_king_location[1],moves,'b')
if len(moves)==0: #either check mate or stealmate
if self.has_check():
self.check_mate=True
else:
self.steale_mate=True
else:
self.check_mate=False
self.steale_mate=False
return moves
'''
determine if current player in check
if player in check need to remove check otherwise game over
'''
def check_for_pins_and_checks(self):
pins=[]
checks=[]
incheck=False
if self.whiteToMove:
my_color='w'
enemy_color='b'
start_row,start_col = self.white_king_location
else:
my_color='b'
enemy_color='w'
start_row,start_col = self.black_king_location
for j,(x,y) in enumerate(self.king_directions):
possible_pins = ()
for i in range(1,8):
new_x,new_y = start_row+ x*i , start_col + y*i
if self.is_valid_square(new_x,new_y):
end_peice = self.board[new_x][new_y]
if end_peice[0]==my_color and end_peice[1]!='K':
if possible_pins == (): #first pin could be found
possible_pins = (new_x,new_y,x,y) #
else: # 2nd allied peice or no pins break
break
elif end_peice[0] == enemy_color :
type = end_peice[1]
#5 possibilities here in this complex situation
# orthogonnaly rook
# diagonally king
#anywhere king
# pawn or king at one square distance
#any direction 1 square away and peice is a king (necessary to not to go in other king's controlled square)
if (0<=j<=3 and type=='R') or \
(4<=j<=7 and type=='B') or \
(type=='Q') or \
(i==1 and type=='K') or \
(i==1 and type=='p' and (
(enemy_color=='w' and j in [6,7]) or
(enemy_color=='b' and j in [4,5])
)):
if possible_pins == ():
incheck = True
checks.append((new_x,new_y,x,y))
else:
pins.append(possible_pins)
break
else:
break
else:
break
for x,y in self.knight_directions:
new_x,new_y = start_row + x,start_col + y
if self.is_valid_square(new_x,new_y):
end_peice = self.board[new_x][new_y]
if end_peice[1]== 'N' and end_peice[0]==enemy_color: #kinght attack king
incheck=True
checks.append((new_x,new_y,x,y))
return incheck,pins,checks
def has_check(self):
if self.whiteToMove:
return self.square_under_attack(self.white_king_location[0],self.white_king_location[1])
else:
return self.square_under_attack(self.black_king_location[0],self.black_king_location[1])
pass
'''
this determines if enemy can attack this square
'''
def square_under_attack(self,r,c):
self.whiteToMove = not self.whiteToMove #change to my opponent
opp_moves = self.get_all_possible_moves()
for move in opp_moves:
if move.end_row == r and move.end_col == c:
self.whiteToMove = not self.whiteToMove
return True
self.whiteToMove = not self.whiteToMove
return False
'''
all moves without checks
for each possible move check to see if it is a valid move by doing the following
make a move
generate moves for opposite player
see if any of ur moves ur king is attacked
king is move add valid move to the list
'''
def get_all_possible_moves(self):
moves=[]
for r in range(len(self.board)):
for c in range(len(self.board[r])):
turn = self.board[r][c][0]
if (turn == 'w' and self.whiteToMove) or (turn=='b' and not self.whiteToMove):
peice = self.board[r][c][1]
self.move_functions[peice](r,c,moves) #calls the appropriate move functions
return moves
'''
this func return the pawn moves for particular pawn
'''
def get_pawn_moves(self,r,c,moves: list):
peice_pinned = False
pin_direction = ()
for i in range(len(self.pins)-1,-1,-1):
if self.pins[i][0] == r and self.pins[i][1]==c:
peice_pinned=True
pin_direction = (self.pins[i][2],self.pins[i][3])
self.pins.remove(self.pins[i])
break
if self.whiteToMove:
if r == 6 :
if not peice_pinned or pin_direction == (-1,0):
if self.board[4][c]=='--' and self.board[5][c]=='--':
moves.append(Move((6,c),(4,c),self.board))
if self.board[r-1][c]=='--':
if not peice_pinned or pin_direction == (-1,0):
moves.append(Move((r,c),(r-1,c),self.board))
if c>=1:
if not peice_pinned or pin_direction == (-1,-1):
if self.board[r-1][c-1][0]=='b':
moves.append(Move((r,c),(r-1,c-1),self.board))
elif (r-1,c-1)==self.empassant_moves:
moves.append(Move((r,c),(r-1,c-1),self.board,is_empassant_move=True))
if c<=6 :
if not peice_pinned or pin_direction == (-1,+1):
if self.board[r-1][c+1][0]=='b':
moves.append(Move((r,c),(r-1,c+1),self.board))
elif (r-1,c+1)==self.empassant_moves:
moves.append(Move((r,c),(r-1,c+1),self.board,is_empassant_move=True))
else :
if r<=6:
if not peice_pinned or pin_direction == (1,0):
if self.board[r+1][c]=='--':
moves.append(Move((r,c),(r+1,c),self.board))
if r == 1:
if self.board[3][c]=='--' and self.board[2][c]=='--':
moves.append(Move((1,c),(3,c),self.board))
if not peice_pinned or pin_direction == (1,-1):
if c>=1:
if self.board[r+1][c-1][0]=='w':
moves.append(Move((r,c),(r+1,c-1),self.board))
elif (r+1,c-1)==self.empassant_moves:
moves.append(Move((r,c),(r+1,c-1),self.board,is_empassant_move=True))
if not peice_pinned or pin_direction == (1,1):
if c<=6 :
if self.board[r+1][c+1][0]=='w':
moves.append(Move((r,c),(r+1,c+1),self.board))
elif (r+1,c+1)==self.empassant_moves:
moves.append(Move((r,c),(r+1,c+1),self.board,is_empassant_move=True))
return moves
'''
this func return the rook moves for particular rook
'''
def get_rook_moves(self,r,c,moves):
peice_pinned = False
pin_direction = ()
for i in range(len(self.pins)-1,-1,-1):
if self.pins[i][0] == r and self.pins[i][1]==c:
peice_pinned=True
pin_direction = (self.pins[i][2],self.pins[i][3])
if self.board[r][c][1]!='Q': #cannot remove queen from pin on rook moves ,onl remove it from bishop moves
self.pins.remove(self.pins[i])
break
if self.whiteToMove:
ur_symbol= 'w'
opp = 'b'
else:
ur_symbol= 'b'
opp = 'w'
for x,y in [(-1,0),(1,0),(0,1),(0,-1)]:
for i in range(1,8):
new_x,new_y = r + x*i ,c + y*i
if not self.is_valid_square(new_x,new_y):
break
else:
if not peice_pinned or pin_direction == (x,y) or pin_direction == (-x,-y):
if self.board[new_x][new_y][0]=='-':
moves.append(Move((r,c),(new_x,new_y),self.board))
elif self.board[new_x][new_y][0]==opp:
moves.append(Move((r,c),(new_x,new_y),self.board))
break
else :
break
return moves
'''
this func return the knight moves for particular rook
'''
def get_knight_moves(self,r,c,moves):
peice_pinned = False
for i in range(len(self.pins)-1,-1,-1):
if self.pins[i][0] == r and self.pins[i][1]==c:
peice_pinned=True
self.pins.remove(self.pins[i])
break
if self.whiteToMove:
ur_symbol= 'w'
opp = 'b'
else:
ur_symbol= 'b'
opp = 'w'
for x,y in self.knight_directions:
new_x,new_y = r+x,c+y
if (self.is_valid_square(new_x,new_y)):
if not peice_pinned:
if self.board[new_x][new_y][0]!=ur_symbol:
moves.append(Move((r,c),(new_x,new_y),self.board))
return moves
'''
this func return the bishop moves for particular rook
'''
def get_bishop_moves(self,r,c,moves):
peice_pinned = False
pin_direction = ()
for i in range(len(self.pins)-1,-1,-1):
if self.pins[i][0] == r and self.pins[i][1]==c:
peice_pinned=True
pin_direction = (self.pins[i][2],self.pins[i][3])
self.pins.remove(self.pins[i])
break
if self.whiteToMove:
ur_symbol= 'w'
opp = 'b'
else:
ur_symbol= 'b'
opp = 'w'
for x,y in self.bishop_directions:
for i in range(1,8):
new_x,new_y = r + x*i ,c + y*i
if not self.is_valid_square(new_x,new_y):
break
else:
if not peice_pinned or pin_direction == (x,y) or pin_direction == (-x,-y):
if self.board[new_x][new_y][0]=='-':
moves.append(Move((r,c),(new_x,new_y),self.board))
elif self.board[new_x][new_y][0]==opp:
moves.append(Move((r,c),(new_x,new_y),self.board))
break
else :
break
return moves
'''
this func return the king moves for particular king
'''
def get_king_moves(self,r,c,moves):
if self.whiteToMove:
ur_symbol= 'w'
opp = 'b'
else:
ur_symbol= 'b'
opp = 'w'
for x,y in self.king_directions:
new_x,new_y = r+x,c+y
if (self.is_valid_square(new_x,new_y)):
if self.board[new_x][new_y][0]!=ur_symbol:
if ur_symbol == 'w':
self.white_king_location = (new_x,new_y)
else:
self.black_king_location = (new_x,new_y)
incheck,pins,checks = self.check_for_pins_and_checks() #check for pins and checks and if not add the move
if not incheck:
moves.append(Move((r,c),(new_x,new_y),self.board))
if ur_symbol == 'w':
self.white_king_location = (r,c)
else:
self.black_king_location = (r,c) # place king in original position
return moves
'''
this func return the queen moves for particular rook
'''
def get_queen_moves(self,r,c,moves):
return self.get_bishop_moves(r,c,moves) + self.get_rook_moves(r,c,moves)
'''
generate all castle moves
'''
def get_castle_moves(self,r,c,moves,my_color):
if self.square_under_attack(r,c):
return # cannot castle if king is in check
if (self.whiteToMove and self.current_castling_rights.wks) or (not self.whiteToMove and self.current_castling_rights.bks):
self.king_side_castle_moves(r,c,moves,my_color)
if (self.whiteToMove and self.current_castling_rights.wqs) or (not self.whiteToMove and self.current_castling_rights.bqs):
self.queen_side_castle_moves(r,c,moves,my_color)
def king_side_castle_moves(self,r,c,moves,my_color):
if c + 2 <= 7:
if self.board[r][c+1]== '--' and self.board[r][c+2]== '--':
if not self.square_under_attack(r,c+1) and not self.square_under_attack(r,c+2):
moves.append ( Move((r,c),(r,c+2),self.board,castle=True))
def queen_side_castle_moves(self,r,c,moves,my_color):
if c-3 >=0:
if self.board[r][c-1]== '--' and self.board[r][c-2]== '--' and self.board[r][c-3]== '--':
if not self.square_under_attack(r,c-1) and not self.square_under_attack(r,c-2) :
moves.append ( Move((r,c),(r,c-2),self.board,castle=True))
'''
make castling right class other wise difficult to include it in main code
'''
class Castling_Rights():
def __init__(self,wks,wqs,bks,bqs):
self.bks=bks
self.bqs=bqs
self.wks=wks
self.wqs=wqs
class Move():
ranks_to_rows = {
'1':7,'2':6,'3':5,'4':4,'5':3,'6':2,'7':1,'8':0}
rows_to_ranks = {v:k for k,v in ranks_to_rows.items()}
files_to_cols = {chr(97+i):i for i in range(8)}
cols_to_files={v:k for k,v in files_to_cols.items()}
def __init__(self,startsq,endsq,board,choice='Q',is_empassant_move=False,castle=False): #for undowing the move its better to store the board information
self.start_row = startsq[0]
self.start_col = startsq[1]
self.end_row = endsq[0]
self.end_col = endsq[1]
self.peice_moved = board[self.start_row][self.start_col]
self.peice_captured = board[self.end_row][self.end_col]
self.is_pawn_promotion = False
if (self.peice_moved == 'wp' and self.end_row==0) or (self.peice_moved == 'bp' and self.end_row==7):
self.is_pawn_promotion=True
self.promotion_choice =choice
self.is_empassant_move=False
if is_empassant_move:
self.is_empassant_move=True
self.peice_captured = 'wp' if self.peice_moved =='bp' else 'bp'
self.castle=castle
self.is_capture = self.peice_captured!='--'
self.move_id = self.start_row*1000 + self.start_col * 100 + self.end_row * 10 + self.end_col # generate unique id and since all below 10 we can do this
#have to tell python if two moves are equal
'''
over writing a method
other wise python check and they are two different objects
'''
def __eq__(self, value):
if isinstance(value,Move):
return value.move_id == self.move_id
return False
def get_chess_notation(self):
#make it to look move in chess notation
return self.get_rank_file(self.start_row,self.start_col) + self.get_rank_file(self.end_row,self.end_col)
def get_rank_file(self,r,c):
return self.cols_to_files[c]+ self.rows_to_ranks[r] #first column than row
def __str__(self):
#castle move
if self.castle:
return "o-o" if self.end_col==6 else 'o-o-o'
end_square = self.get_rank_file(self.end_row,self.end_col)
#pawn move
if self.peice_moved[1] == 'p':
if self.is_capture:
return self.cols_to_files[self.start_col] + 'x'+ end_square + f""" {self.peice_moved} from {self.get_rank_file(self.start_row, self.start_col)} to {self.get_rank_file(self.end_row, self.end_col)}"""
else:
return end_square+ f""" {self.peice_moved} from {self.get_rank_file(self.start_row, self.start_col)} to {self.get_rank_file(self.end_row, self.end_col)}"""
# pawn promotion
#Nbd2 both knights can move to d2
# for check and checkmate
# peice moves
move_string = self.peice_moved[1]
if self.is_capture:
move_string+='x'
return move_string + end_square + f""" {self.peice_moved} from {self.get_rank_file(self.start_row, self.start_col)} to {self.get_rank_file(self.end_row, self.end_col)}"""