How to get the Value from Bar Chart in PyqtChart

Question

I have implemented a barchart and now want to get the value when double click on bar. I know about slot and signal concept and able to call the function on double click but not sure what parameter i should use to get the values. Here is the code:

import sys
from PyQt5.QtWidgets import (QApplication, QMainWindow)
from PyQt5.QtChart import QChart, QChartView, QHorizontalBarSeries, QBarSet, QBarCategoryAxis, 
QValueAxis
from PyQt5.Qt import Qt 
from PyQt5.QtGui import QPainter
from PyQt5.QtChart import *


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.resize(800, 600)

        set0 = QBarSet('A')
        set1 = QBarSet('B')
    

        set0.append([1, 2, 3, 4, 5, 6])
        set1.append([5, 0, 0, 4, 0, 7])

        series = QBarSeries()
        series.append(set0)
        series.append(set1)
    

        chart = QChart(
        chart.addSeries(series)
        chart.setTitle('ABC')

        chart.setAnimationOptions(QChart.SeriesAnimations)

        technology = ('Oracle', 'Teradata')

        axisY = QValueAxis()
        axisY.applyNiceNumbers()
        chart.addAxis(axisY, Qt.AlignLeft)
        series.attachAxis(axisY)

        axisX = QBarCategoryAxis()
        axisX.append(technology)
        chart.addAxis(axisX, Qt.AlignBottom)
        series.attachAxis(axisX)

    
        chart.legend().setVisible(True)
        chart.legend().setAlignment(Qt.AlignBottom)

        chartView = QChartView(chart)
        chartView.setRenderHint(QPainter.Antialiasing)
        self.setCentralWidget(chartView)

        series.doubleClicked.connect(self.bar_double_clicked)


    def bar_double_clicked(self, axisX,technology):
        print(axisX )

if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

score 1 · Answer 1 · answered Jul 01 '21 at 22:45

You have to use the index and the QBarSet to get the information.

import sys

from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPainter
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtChart import (
    QChart,
    QChartView,
    QBarSeries,
    QBarSet,
    QBarCategoryAxis,
    QValueAxis,
)


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.resize(800, 600)

        set0 = QBarSet("A")
        set1 = QBarSet("B")

        set0.append([1, 2, 3, 4, 5, 6])
        set1.append([5, 0, 0, 4, 0, 7])

        series = QBarSeries()
        series.append(set0)
        series.append(set1)

        chart = QChart()
        chart.addSeries(series)
        chart.setTitle("ABC")

        chart.setAnimationOptions(QChart.SeriesAnimations)

        technologies = [f"technology-{i}" for i in range(6)]

        axisY = QValueAxis()
        axisY.applyNiceNumbers()
        chart.addAxis(axisY, Qt.AlignLeft)
        series.attachAxis(axisY)

        self.axis_x = QBarCategoryAxis()
        self.axis_x.append(technologies)
        chart.addAxis(self.axis_x, Qt.AlignBottom)
        series.attachAxis(self.axis_x)

        chart.legend().setVisible(True)
        chart.legend().setAlignment(Qt.AlignBottom)

        chartView = QChartView(chart)
        chartView.setRenderHint(QPainter.Antialiasing)
        self.setCentralWidget(chartView)

        series.doubleClicked.connect(self.bar_double_clicked)

    def bar_double_clicked(self, index, barset):
        print(barset.label(), barset.at(index), self.axis_x.categories()[index])


if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

How to get the Value from Bar Chart in PyqtChart

1 Answers1