PyQt5：如何使用布局或几何继承小部件？

Question

我在form.ui中放了一个QLineEdit，我想用CustomLabel来继承它。但是我的主窗口中有2个QLineEdit（lines in form.ui和CustomLabel）。

我应该如何处理这种情况？

Here is the image of my programme

这是我的代码：

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QLineEdit, QLabel
from PyQt5.QtGui import QIcon
from PyQt5.QtCore import pyqtSlot
import PyQt5.uic as uic


form_ui,_ =uic.loadUiType('form.ui')
print(type(form_ui))
class Mainwindow(QWidget,form_ui):
    """docstring for App"""
    def __init__(self):
        super(Mainwindow, self).__init__()
        self.setupUi(self)

        path_lineEdit = CustomLabel(self.lines)

class CustomLabel(QLineEdit):

    def __init__(self,parent=None):
        super(CustomLabel,self).__init__(parent)
        # self.resize(parent.size())

    def dragEnterEvent(self, e):
        if e.mimeData().hasFormat('text/plain'):
            e.accept()
        else:
            e.ignore()

    def dropEvent(self, e):
        self.setText('212'+e.mimeData().text())


if __name__ == '__main__':

    app = QApplication(sys.argv)
    ex = Mainwindow()
    ex.show()
    sys.exit(app.exec_())