Displaying pandas dataframe in QML

Question

I have 2 pandas dataframes, one with 6 rows and 7 columns and another one with 21 rows and 12 columns, i would like to display them using QML, while googling i got to know about TableView TableView QML Type. In that example, the data has been entered already in ListElement and it is being shown. But in my case the data is from python pandas dataframe, how can i fetch the columns and rows from pandas straight into QML, should i create those columns well before under listelement? Any help would be appreciated

Note: I have used QtWidgets to display dataframe, it was just a drag and drop tableview and use the model created and set them using tableView.setModel(model). But i am kind of clueless here in QML

Answer 1

You can create a class that inherits from QAbstractTableModel as implemented in this old answer and use the QTableView of QtQuick 2.12 that was released in Qt 5.12 since it supports the QAbstractTableModel type model, so you will have to use the latest versions of PyQt5.

main.py

from PyQt5 import QtCore, QtGui, QtQml
import numpy as np
import pandas as pd

class DataFrameModel(QtCore.QAbstractTableModel):
    DtypeRole = QtCore.Qt.UserRole + 1000
    ValueRole = QtCore.Qt.UserRole + 1001

    def __init__(self, df=pd.DataFrame(), parent=None):
        super(DataFrameModel, self).__init__(parent)
        self._dataframe = df

    def setDataFrame(self, dataframe):
        self.beginResetModel()
        self._dataframe = dataframe.copy()
        self.endResetModel()

    def dataFrame(self):
        return self._dataframe

    dataFrame = QtCore.pyqtProperty(pd.DataFrame, fget=dataFrame, fset=setDataFrame)

    @QtCore.pyqtSlot(int, QtCore.Qt.Orientation, result=str)
    def headerData(self, section: int, orientation: QtCore.Qt.Orientation, role: int = QtCore.Qt.DisplayRole):
        if role == QtCore.Qt.DisplayRole:
            if orientation == QtCore.Qt.Horizontal:
                return self._dataframe.columns[section]
            else:
                return str(self._dataframe.index[section])
        return QtCore.QVariant()

    def rowCount(self, parent=QtCore.QModelIndex()):
        if parent.isValid():
            return 0
        return len(self._dataframe.index)

    def columnCount(self, parent=QtCore.QModelIndex()):
        if parent.isValid():
            return 0
        return self._dataframe.columns.size

    def data(self, index, role=QtCore.Qt.DisplayRole):
        if not index.isValid() or not (0 <= index.row() < self.rowCount() \
            and 0 <= index.column() < self.columnCount()):
            return QtCore.QVariant()
        row = self._dataframe.index[index.row()]
        col = self._dataframe.columns[index.column()]
        dt = self._dataframe[col].dtype

        val = self._dataframe.iloc[row][col]
        if role == QtCore.Qt.DisplayRole:
            return str(val)
        elif role == DataFrameModel.ValueRole:
            return val
        if role == DataFrameModel.DtypeRole:
            return dt
        return QtCore.QVariant()

    def roleNames(self):
        roles = {
            QtCore.Qt.DisplayRole: b'display',
            DataFrameModel.DtypeRole: b'dtype',
            DataFrameModel.ValueRole: b'value'
        }
        return roles

if __name__ == "__main__":
    import os
    import sys

    app = QtGui.QGuiApplication(sys.argv)
    df = pd.DataFrame(np.random.randint(0, 100, size=(6, 7)), columns=list('ABCDEFG'))
    print(df)
    model = DataFrameModel(df)
    engine = QtQml.QQmlApplicationEngine()
    engine.rootContext().setContextProperty("table_model", model)
    qml_path = os.path.join(os.path.dirname(__file__), "main.qml")
    engine.load(QtCore.QUrl.fromLocalFile(qml_path))
    if not engine.rootObjects():
        sys.exit(-1)
    engine.quit.connect(app.quit)
    sys.exit(app.exec_())

main.qml

import QtQuick 2.12
import QtQuick.Controls 2.4
import QtQuick.Window 2.11

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
    color: '#222222'

    TableView {
        id: tableView

        columnWidthProvider: function (column) { return 100; }
        rowHeightProvider: function (column) { return 60; }
        anchors.fill: parent
        leftMargin: rowsHeader.implicitWidth
        topMargin: columnsHeader.implicitHeight
        model: table_model
        delegate: Rectangle {
            color: parseFloat(display) > 50 ? 'green' : 'red'
            Text {
                text: display
                anchors.fill: parent
                anchors.margins: 10
                color: 'white'
                font.pixelSize: 15
                verticalAlignment: Text.AlignVCenter
            }
        }
        Rectangle { // mask the headers
            z: 3
            color: "#222222"
            y: tableView.contentY
            x: tableView.contentX
            width: tableView.leftMargin
            height: tableView.topMargin
        }

        Row {
            id: columnsHeader
            y: tableView.contentY
            z: 2
            Repeater {
                model: tableView.columns > 0 ? tableView.columns : 1
                Label {
                    width: tableView.columnWidthProvider(modelData)
                    height: 35
                    text: table_model.headerData(modelData, Qt.Horizontal)
                    color: '#aaaaaa'
                    font.pixelSize: 15
                    padding: 10
                    verticalAlignment: Text.AlignVCenter

                    background: Rectangle { color: "#333333" }
                }
            }
        }
        Column {
            id: rowsHeader
            x: tableView.contentX
            z: 2
            Repeater {
                model: tableView.rows > 0 ? tableView.rows : 1
                Label {
                    width: 40
                    height: tableView.rowHeightProvider(modelData)
                    text: table_model.headerData(modelData, Qt.Vertical)
                    color: '#aaaaaa'
                    font.pixelSize: 15
                    padding: 10
                    verticalAlignment: Text.AlignVCenter

                    background: Rectangle { color: "#333333" }
                }
            }
        }

        ScrollIndicator.horizontal: ScrollIndicator { }
        ScrollIndicator.vertical: ScrollIndicator { }
    }
}

I have used:

• Python 3.7.2
• PyQt5 5.12.1
• Qt 5.12.2
• pandas 0.24.1