pyQT5实现：在mywindow主窗口弹出windows的cmd窗口

可以通过使用QProcess类来实现在mywindow主窗口弹出cmd窗口。具体实现方法可以参考以下代码：

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QTextEdit, QAction
from PyQt5.QtCore import QProcess

class MyWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.textEdit = QTextEdit()
        self.setCentralWidget(self.textEdit)

        cmdAction = QAction('Open CMD', self)
        cmdAction.triggered.connect(self.openCMD)
        self.toolbar = self.addToolBar('Open CMD')
        self.toolbar.addAction(cmdAction)

        self.setGeometry(300, 300, 350, 250)
        self.setWindowTitle('My Window')
        self.show()

    def openCMD(self):
        process = QProcess(self)
        process.start('cmd.exe')
        process.readyReadStandardOutput.connect(self.onReadyReadStandardOutput)
        process.readyReadStandardError.connect(self.onReadyReadStandardError)

    def onReadyReadStandardOutput(self):
        process = self.sender()
        output = process.readAllStandardOutput().data().decode()
        self.textEdit.insertPlainText(output)

    def onReadyReadStandardError(self):
        process = self.sender()
        output = process.readAllStandardError().data().decode()
        self.textEdit.insertPlainText(output)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = MyWindow()
    sys.exit(app.exec_())

当点击工具栏中的“Open CMD”按钮时，会在mywindow主窗口中弹出cmd窗口。注意，在Windows系统中需要使用cmd.exe命令来打开命令行窗口。