在pyqt中显示运行时输出

Question

I have python code for simple displaying the output in the mainwindow after clicking the pushbutton. Here is my code:

from PyQt4 import QtCore, QtGui
import time

try:
  _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
  _fromUtf8 = lambda s: s

class Ui_MainWindow(object):
  def setupUi(self, MainWindow):
    MainWindow.setObjectName(_fromUtf8("MainWindow"))
    MainWindow.resize(176, 156)
    self.centralWidget = QtGui.QWidget(MainWindow)
    self.centralWidget.setObjectName(_fromUtf8("centralWidget"))
    self.gridLayout = QtGui.QGridLayout(self.centralWidget)
    self.gridLayout.setObjectName(_fromUtf8("gridLayout"))
    self.pushButton = QtGui.QPushButton(self.centralWidget)
    self.pushButton.setObjectName(_fromUtf8("pushButton"))
    self.gridLayout.addWidget(self.pushButton, 0, 0, 1, 1)
    self.label = QtGui.QLabel(self.centralWidget)
    self.label.setObjectName(_fromUtf8("label"))
    self.gridLayout.addWidget(self.label, 1, 0, 1, 1)
    MainWindow.setCentralWidget(self.centralWidget)
    self.menuBar = QtGui.QMenuBar(MainWindow)
    self.menuBar.setGeometry(QtCore.QRect(0, 0, 176, 25))
    self.menuBar.setObjectName(_fromUtf8("menuBar"))
    MainWindow.setMenuBar(self.menuBar)
    self.mainToolBar = QtGui.QToolBar(MainWindow)
    self.mainToolBar.setObjectName(_fromUtf8("mainToolBar"))
    MainWindow.addToolBar(QtCore.Qt.TopToolBarArea, self.mainToolBar)
    self.statusBar = QtGui.QStatusBar(MainWindow)
    self.statusBar.setObjectName(_fromUtf8("statusBar"))
    MainWindow.setStatusBar(self.statusBar)

    self.retranslateUi(MainWindow)
    QtCore.QMetaObject.connectSlotsByName(MainWindow)
    self.pushButton.clicked.connect( self.Out)

  def retranslateUi(self, MainWindow):
    MainWindow.setWindowTitle(QtGui.QApplication.translate("MainWindow", "MainWindow", None, QtGui.QApplication.UnicodeUTF8))
    self.pushButton.setText(QtGui.QApplication.translate("MainWindow", "Start", None, QtGui.QApplication.UnicodeUTF8))
    self.label.setText(QtGui.QApplication.translate("MainWindow", "0.0", None, QtGui.QApplication.UnicodeUTF8))

  def Out(self):
    for i in range(10):
        time.sleep(0.5)
        out = str(i)
        self.label.setText(out)
        if i == 10:
            break
if __name__ == "__main__":
  import sys
  app = QtGui.QApplication(sys.argv)
  MainWindow = QtGui.QMainWindow()
  ui = Ui_MainWindow()
  ui.setupUi(MainWindow)
  MainWindow.show()
  sys.exit(app.exec_())

But i want continuous output in label and it is giving after the executing of program. Please suggest correction in code or any trick. Sorry for weak English.

Answer 1

For your example code, you can use processEvents to keep the gui updated:

def Out(self):
    for i in range(10):
        time.sleep(0.5)
        out = str(i)
        self.label.setText(out)
        QtGui.qApp.processEvents()
        if i == 10:
            break