How do I set QModelIndex to emit QAbstractTableModel.dataChanged in PyQT?

Question

I want to refresh content of QTableView when model data changed.
But I can't find a way of specificing the value of QModelIndex instance.
See questions in below code.

from PyQt5 import QtWidgets, QtCore
from PyQt5.QtCore import QModelIndex, Qt

class MyTableModel(QtCore.QAbstractTableModel):
    def __init__(self, data=[[]], parent=None):
        super().__init__(parent)
        self.data = data
...
data = [
    [1, 2],
    [3, 4],
]
model = MyTableModel(data)
view = QtWidgets.QTableView()
view.setModel(model)

# changing a data element at row 1, column 0
data[1][0] = 30

row_index = QModelIndex()
# Question: how do I set row_index as 1?
col_index = QModelIndex()
# Question: how do I set col_index as 0?
model.dataChanged.emit(row_index, col_index, Qt.DisplayRole)

Answer 1

The index method of model is for that.

row_index = model.index(1, 0)
col_index = model.index(1, 0)
model.dataChanged.emit(row_index, col_index, Qt.DisplayRole)