adding row number to QTableView in pyside2 - qt

Question

is there any way I could add a row number beside the QTableView just for info and not actually add it into the data so that I could export it without the row number as a new column? it seems like everyone has it on default while mine is not showing at all. i tried tableView.verticalHeader().setVisible(True) but it isn't working. looked everywhere in the docs also wasn't mentioned, maybe I missed it
here's what I've tried so far
from PySide2.QtWidgets import *
from PySide2.QtGui import *
from PySide2.QtCore import *
import pandas as pd
class MyWindow(QWidget):
def __init__(self, parent=None, data=None):
QWidget.__init__(self, parent)
self.setGeometry(300, 200, 570, 450)
self.setWindowTitle('MyWindow')
data = {'name': ['abdul','budi','cindy'],'ID':[1,2,3], 'balance': [100,200,300]}
df = pd.DataFrame(data)
self.model = PandasModel(df)
self.table_view = QTableView()
self.table_view.setModel(self.model)
layout = QVBoxLayout(self)
layout.addWidget(self.table_view)
self.setLayout(layout)
self.table_view.verticalHeader().setVisible(True)
self.table_view.verticalHeader().show()
class PandasModel(QAbstractTableModel):
"""
Class to populate a table view with a pandas dataframe
"""
def __init__(self, data, parent=None):
QAbstractTableModel.__init__(self, parent)
self._data = data
def rowCount(self, parent=None):
return self._data.shape[0]
def columnCount(self, parent=None):
return self._data.shape[1]
def data(self, index, role=Qt.DisplayRole):
if index.isValid():
if role == Qt.DisplayRole:
return str(self._data.iloc[index.row(), index.column()])
return None
def headerData(self, col, orientation, role):
if orientation == Qt.Horizontal and role == Qt.DisplayRole:
return self._data.columns[col]
return None
if __name__ == "__main__":
app = QApplication([])
UI = MyWindow()
UI.show()
sys.exit(app.exec_())

Answer 1

You can just return the row number in your headerData implementation like:
QVariant MyTable::headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const
{
if (orientation == Qt::Vertical && role == Qt::DisplayRole)
return section;
return QAbstractItemModel::headerData(section, orientation, role);
}

Answer 2

The python approach from László Papp's answer. Turns out I have to add another if conditional statement for the vertical header as an index
def headerData(self, col, orientation, role):
if orientation == Qt.Horizontal and role == Qt.DisplayRole:
return self._data.columns[col]
if orientation == Qt.Vertical and role == Qt.DisplayRole:
return self._data.index[col]+1
return None