Text Indent doesn't works - qt

Question

The program does not work changing the paragraph indentation in the text. I want the text to always be indented in TextEdit. If do not use other widgets than TextEdit, then everything works.I think that there are problems with layouts, but I can’t understand, because I don’t really understand Python, but this problem needs to be solved. What could be the problem?
PyQt5 import QtCore, QtGui, QtWidgets
import os
from PyQt5.QtWidgets import QTextEdit, QApplication
from PyQt5.QtGui import QTextDocument, QTextCursor, QTextBlockFormat
class TextEditor(QTextEdit):
def __init__(self,parent):
super().__init__(parent)
self.initUI()
def initUI(self):
cursor = QTextCursor(self.document())
cursor.select(QTextCursor.Document)
fmt = QTextBlockFormat()
fmt.setTextIndent(60)
cursor.mergeBlockFormat(fmt)
font= QtGui.QFont()
font.setFamily("Times New Roman")
font.setPointSize(14)
self.setFont(font)
self.show()
def insertFromMimeData(self, md):
cursor = self.textCursor()
fmt = QTextBlockFormat()
fmt.setTextIndent(cursor.blockFormat().textIndent())
cursor.mergeBlockFormat(fmt)
cursor.insertText(md.text())
class Ui_mainWindow(object):
def setupUi(self, mainWindow):
mainWindow.setObjectName("mainWindow")
mainWindow.resize(800, 600)
self.centralwidget = QtWidgets.QWidget(mainWindow)
self.centralwidget.setObjectName("centralwidget")
self.gridLayout = QtWidgets.QGridLayout(self.centralwidget)
self.gridLayout.setObjectName("gridLayout")
self.horizontalLayout_2 = QtWidgets.QHBoxLayout()
self.horizontalLayout_2.setObjectName("horizontalLayout_2")
self.textEdit = TextEditor(self.centralwidget)
self.textEdit.setObjectName("textEdit")
self.horizontalLayout_2.addWidget(self.textEdit)
self.gridLayout.addLayout(self.horizontalLayout_2, 2, 0, 1, 1)
self.horizontalLayout = QtWidgets.QHBoxLayout()
self.horizontalLayout.setObjectName("horizontalLayout")
self.pushButton = QtWidgets.QPushButton(self.centralwidget)
font = QtGui.QFont()
font.setFamily("Times New Roman")
font.setPointSize(10)
font.setBold(True)
font.setWeight(75)
self.pushButton.setFont(font)
self.pushButton.setObjectName("pushButton")
self.horizontalLayout.addWidget(self.pushButton)
self.pushButton_2 = QtWidgets.QPushButton(self.centralwidget)
font = QtGui.QFont()
font.setFamily("Times New Roman")
font.setPointSize(10)
font.setBold(True)
font.setWeight(75)
self.pushButton_2.setFont(font)
self.pushButton_2.setObjectName("pushButton_2")
self.horizontalLayout.addWidget(self.pushButton_2)
self.gridLayout.addLayout(self.horizontalLayout, 0, 0, 1, 1)
self.label = QtWidgets.QLabel(self.centralwidget)
font = QtGui.QFont()
font.setPointSize(11)
self.label.setFont(font)
self.label.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
self.label.setObjectName("label")
self.gridLayout.addWidget(self.label, 1, 0, 1, 1)
mainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(mainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 21))
self.menubar.setObjectName("menubar")
mainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(mainWindow)
self.statusbar.setObjectName("statusbar")
mainWindow.setStatusBar(self.statusbar)
self.pig()
self.retranslateUi(mainWindow)
QtCore.QMetaObject.connectSlotsByName(mainWindow)
self.butclick()
self.butclick2()
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())