用python pyqt5界面开发写一段包含登录界面和修改个人信息界面和注销界面的python代码

这里提供一个简单的示例代码，仅供参考：

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QLineEdit, QPushButton, QMessageBox

class LoginWindow(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle('Login')
        self.resize(300, 200)

        self.label_username = QLabel('Username:', self)
        self.label_username.move(50, 50)
        self.edit_username = QLineEdit(self)
        self.edit_username.move(120, 50)

        self.label_password = QLabel('Password:', self)
        self.label_password.move(50, 80)
        self.edit_password = QLineEdit(self)
        self.edit_password.setEchoMode(QLineEdit.Password)
        self.edit_password.move(120, 80)

        self.button_login = QPushButton('Login', self)
        self.button_login.move(100, 130)
        self.button_login.clicked.connect(self.handle_login)

        self.show()

    def handle_login(self):
        username = self.edit_username.text()
        password = self.edit_password.text()
        if username == 'admin' and password == 'admin':
            self.hide()
            self.edit_username.setText('')
            self.edit_password.setText('')
            self.profile_window = ProfileWindow()
            self.profile_window.show()
        else:
            QMessageBox.warning(self, 'Error', 'Invalid username or password!', QMessageBox.Ok)

class ProfileWindow(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle('Profile')
        self.resize(300, 200)

        self.label_username = QLabel('Username:', self)
        self.label_username.move(50, 50)
        self.edit_username = QLineEdit(self)
        self.edit_username.move(120, 50)

        self.label_password = QLabel('Password:', self)
        self.label_password.move(50, 80)
        self.edit_password = QLineEdit(self)
        self.edit_password.setEchoMode(QLineEdit.Password)
        self.edit_password.move(120, 80)

        self.button_update = QPushButton('Update', self)
        self.button_update.move(100, 130)
        self.button_update.clicked.connect(self.handle_update)

        self.button_logout = QPushButton('Logout', self)
        self.button_logout.move(180, 10)
        self.button_logout.clicked.connect(self.handle_logout)

        self.show()

    def handle_update(self):
        username = self.edit_username.text()
        password = self.edit_password.text()
        # TODO: update user info

    def handle_logout(self):
        self.hide()
        self.login_window = LoginWindow()
        self.login_window.show()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    login_window = LoginWindow()
    sys.exit(app.exec_())

这个代码中有两个窗口，一个是登录窗口（`LoginWindow`），一个是个人信息窗口（`ProfileWindow`）。在登录窗口中，用户需要输入用户名和密码，如果登录成功，则跳转到个人信息窗口。在个人信息窗口中，用户可以修改个人信息，也可以注销并返回登录窗口。这里的代码还比较简单，实际项目中可能需要更复杂的逻辑处理。