ошибка spindemo is not defined

import sys
from PyQt5.QtCore import * from PyQt5.QtGui import * from PyQt5.QtWidgets import * class spindemo(QWidget):
def init (self, parent = None):
super(spindemo,self). init (parent)
layout = QVBoxLayout()
self.l1 = QLabel("текущее значение")
self.l1.setAligment(Qt.AlignCenter)
layout = addWidget(self.l1)
self.sp = QSpinBox()
layout = addWidget(self.sp)
self.sp.valueChanged.connect(self.valuechange)
self.setLayout(layout)
self.setWindowTitle(" демонстрация")
def valuechange(self):
self.l1.setText( " Текущее значение :"+ self.sp.value())
def main():
app = QApplication(sys.argv)
ex = spindemo()
ex.show()
sys.exit(app.exec_())
if name == ' main ':
main()

```