Chess FEN to bitboard conversion in python

import chess
import numpy as np
board = chess.Board('rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1')

w_pawn = (np.asarray(board.pieces(chess.PAWN, chess.WHITE).tolist())).astype(int)
w_rook = (np.asarray(board.pieces(chess.ROOK, chess.WHITE).tolist())).astype(int)
w_knight = (np.asarray(board.pieces(chess.KNIGHT, chess.WHITE).tolist())).astype(int)
w_bishop = (np.asarray(board.pieces(chess.BISHOP, chess.WHITE).tolist())).astype(int)
w_queen = (np.asarray(board.pieces(chess.QUEEN, chess.WHITE).tolist())).astype(int)
w_king = (np.asarray(board.pieces(chess.KING, chess.WHITE).tolist())).astype(int)

b_pawn = (np.asarray(board.pieces(chess.PAWN, chess.BLACK).tolist())).astype(int)
b_rook = (np.asarray(board.pieces(chess.ROOK, chess.BLACK).tolist())).astype(int)
b_knight = (np.asarray(board.pieces(chess.KNIGHT, chess.BLACK).tolist())).astype(int)
b_bishop = (np.asarray(board.pieces(chess.BISHOP, chess.BLACK).tolist())).astype(int)
b_queen = (np.asarray(board.pieces(chess.QUEEN, chess.BLACK).tolist())).astype(int)
b_king = (np.asarray(board.pieces(chess.KING, chess.BLACK).tolist())).astype(int)

print( np.concatenate((w_pawn, w_rook, w_knight, w_bishop, w_queen, w_king,
                       b_pawn, b_rook, b_knight, b_bishop, b_queen, b_king)))


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