Sqlite中用python获取数据库数据行数的cursor.rowcount为什么一直返回-1

Question

问题遇到的现象和发生背景

本人，在学习python中，尝试在SQlite下利用cursor.rowcount来获取数据的行数，但是一直都返回-1，求各位指点一下。谢谢

问题相关代码，请勿粘贴截图

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import *
import sqlite3

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")

        conn = sqlite3.connect("mrsoft.db")
        cursor = conn.cursor()
        cursor.execute('select * from user')
        recult = cursor.fetchall()
        print(recult)
        print(cursor.rowcount)
        cursor.close()
        conn.close()

        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))

if __name__ == '__main__':
    import sys
    app=QtWidgets.QApplication(sys.argv)
    MainWindow=QtWidgets.QMainWindow()
    ui=Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

运行结果及报错内容

E:\python_work\venv\Scripts\python.exe E:/python_work/Demo10/10.11/10.11.py
[(1, 'MRSOFT'), (2, 'Andy'), (3, '明日科技小助手')]
-1

进程已结束，退出代码为 0

我的解答思路和尝试过的方法

我想要达到的结果

Answer 1

重新获取一次
cursor.execute("select seq from sqlite_sequence where name = 'user'")
print(cursor.fetchone()[0])