why I cannot use a attribute that import from another py file?

I want to make a Gomoku game with PyCharm and PyQt5

I write game logic in game.py and write game graphic interface in window.py.

In game.py, I define g_map to save data .and in window.py I import game to draw chess pieces .

However, I cannot make it for the error:

AttributeError: 'GomokuWindow' object has no attribute 'g'

game.py

class Gomoku:
    def __init__(self):
        self.g_map=[[0 for y in range(15)] for x in range(15) ]# current chess board if 0 None if 1 white,if 2 black 
        self.cur_step=0 # current step 

window.py

from PyQt5.QtCore import Qt
from PyQt5.QtCore import QPoint
from PyQt5.QtGui import QPen, QColor ,QPainter
from PyQt5.QtWidgets import  QMainWindow

#######################################################################
from game import Gomoku  # here i import Gomoku  class
#######################################################################

class GomokuWindow(QMainWindow):   

    def __init__(self):
        super().__init__()
        self.init_ui() 
########################################################################
        self.g = Gomoku() # I Create member variables || i need Gomoku().g_map
########################################################################

    def init_ui(self):

        self.setObjectName('Main Window')
        self.setWindowTitle("五子棋")

        self.setFixedSize(650,650)
                self.setStyleSheet("QMainWindow{background-color:green}")

        self.show()
    def paintEvent(self,e):

        qp = QPainter()
        qp.begin(self)
        self.draw_map(qp)
        self.draw_pieces(qp)
        qp.end()


    def draw_map(self,qp):
        qp.setPen(QPen(Qt.black, 2, Qt.SolidLine))
        for x in range(15):

            qp.drawLine(40*(x+1),40,40*(x+1),600)

        for y in range(15):
            qp.drawLine(40,40*(y+1),600,40*(y+1))


#######################################################################
in this method i use self.g.g_map
#######################################################################

    def draw_pieces(self,qp):
# i try this:
#       g_map = Gomoku().g_map || its ok 

        qp.setPen(QPen(QColor(0,0,0),1,Qt.SolidLine))
        qp.setBrush(QColor(0,0,0))
        for x in range(15):
            for y in range(15):

#######################################################################
                if self.g.g_map[x][y] == 1:  here
#######################################################################

                    qp.drawEllipse(QPoint(40*(x+1)),40*(y+1),15,15)

        qp.setPen(QPen(QColor(255, 255, 255), 1, Qt.SolidLine))
        qp.setBrush(QColor(255, 255, 255))
        for x in range(15):
            for y in range(15):
                if self.g.g_map[x][y] == 2:
                    qp.drawEllipse(QPoint(40 * (y + 1)), 40 * (y + 1), 15, 15)

Pycharm say this:

"D:\Program Files (x86)\Python38-64\python.exe" D:/pychram/五子棋/main.py
Traceback (most recent call last):
  File "D:\pychram\������\window.py", line 30, in paintEvent
    self.draw_pieces(qp)
  File "D:\pychram\������\window.py", line 54, in draw_pieces
    if self.g.g_map[x][y] == 1:
AttributeError: 'GomokuWindow' object has no attribute 'g'

Process finished with exit code -1073740791 (0xC0000409)

I try to only g_map = Gomoku().g_map in def drawpieces. It's ok, but I need a Gomoku object to finish this game.

seems like paintEvent method calls draw_pieces method before self.g is initialized.

Try moving self.g initialization to the beginning of the init function like this:

def __init__(self):
    super().__init__()
    self.g = Gomoku() # I Create member variables || i need Gomoku().g_map
    self.init_ui()