【pyqtgraph绘图】在pyqtgraph中绘图

from PyQt5.QtWidgets import QPushButton,QWidget,QApplication,QGridLayout,QListWidget,QLineEditimport pyqtgraph as pgimport sysimport numpy as npclass Example(QWidget):    def __init__(self):        super(Example, self).__init__()        self.initUI()        self.linePlot()        self.scatterPlot()        self.three_curves()    def initUI(self):        self.setGeometry(400,400,800,620)        self.setWindowTitle("pyqtgraph快速入门")        ## 创建一些小部件放在顶级窗口中        btn = QPushButton('press me')        text = QLineEdit('enter text')        listw = QListWidget()        listw.addItems(["aa", "bb", "cc"])        self.gridLayout = QGridLayout(self)        ## 将部件添加到布局中的适当位置        self.gridLayout.addWidget(btn, 0, 0)        self.gridLayout.addWidget(text, 1, 0)        self.gridLayout.addWidget(listw, 2, 0)        self.setLayout(self.gridLayout)    def linePlot(self):        plt1 = pg.PlotWidget()        plt1.plot([i for i in range(10)], [i * i for i in range(10)])        self.gridLayout.addWidget(plt1, 0, 1, 1, 1)    def scatterPlot(self):        plt2 = pg.PlotWidget()        x = np.random.normal(size=1000)        y = np.random.normal(size=1000)        plt2.plot(x, y, pen=None, symbol="o")        self.gridLayout.addWidget(plt2, 1, 1, 1, 1)    def three_curves(self):        plt3 = pg.PlotWidget(title="Three plot curves")        x = np.arange(1000)        y = np.random.normal(size=(3, 1000))        for i in range(3):            plt3.plot(x, y[i], pen=(i, 3))  ## setting pen=(i,3) 自动创建3个不同颜色的笔        self.gridLayout.addWidget(plt3, 2, 1, 1, 1)if __name__ == '__main__':    app = QApplication(sys.argv)    ex = Example()    ex.show()    sys.exit(app.exec_())