from PyQt5 import QtWidgets as Qtw
from pyqtgraph.flowchart import Flowchart


class MainWindow(Qtw.QWidget):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        layout = Qtw.QGridLayout()

        # Create flowchart, define input/output terminals
        fc = Flowchart(terminals={
            'Input': {'io': 'in'},
            'Output': {'io': 'out'},
        })

        layout.addWidget(fc.widget())
        self.setLayout(layout)
        self.show()


if __name__ == '__main__':
    import sys
    app = Qtw.QApplication(sys.argv)
    w = MainWindow(windowTitle="create FlowChart")
    sys.exit(app.exec_())