readtxt.py

#!/usr/bin/python
# openfiledialog.py
import sys
from PyQt4 import QtGui, QtCore


class OpenFile(QtGui.QMainWindow):
    def __init__(self, parent = None):
         QtGui.QWidget.__init__(self, parent)
         self.setGeometry(300, 300, 350, 300)
         self.setWindowTitle('OpenFile')
         self.textEdit = QtGui.QTextEdit()
         self.setCentralWidget(self.textEdit)
         self.statusBar()
         self.setFocus()
         exit = QtGui.QAction(QtGui.QIcon('icons/open.png'), 'Open', self)
         exit.setShortcut('Ctrl+O')
         exit.setStatusTip('Open new file')
         self.connect(exit, QtCore.SIGNAL('triggered()'), self.showDialog)
         menubar = self.menuBar()
         file = menubar.addMenu('&File')
         file.addAction(exit)

    def showDialog(self):
         filename = QtGui.QFileDialog.getOpenFileName(self, 'Open file', './')
         file = open(filename)
         data = file.read()
         self.textEdit.setText(data)




app = QtGui.QApplication(sys.argv)
cd = OpenFile()
cd.show()
sys.exit(app.exec_())