New to python and needs some help

'''ps_TextEdit1.py
explore PySide's QTextEdit multiline text entry box
click right mouse button in edit area for popup menu
for undo, cut, copy. paste, select All, etc.
the sample text is loaded using the file dialog widget

PySide is the official LGPL-licensed version of PyQT
you can downloaded the free Windows self-extracting installer
PySide-1.1.0qt474.win32-py2.7.exe
or
PySide-1.1.0qt474.win32-py3.2.exe
from:
http://developer.qt.nokia.com/wiki/PySide_Binaries_Windows
'''

from PySide.QtCore import *
from PySide.QtGui import *

class MyFrame(QWidget):
    def __init__(self, parent=None):
        QWidget.__init__(self, parent)
        # setGeometry(x_pos, y_pos, width, height)
        self.setGeometry(100, 50, 500, 300)
        self.setWindowTitle('QTextEdit() test')

        self.edit = QTextEdit(self)
        self.load_button = QPushButton(self)
        self.load_button.setText('Load a text file')

        # use grid layout manager
        grid = QGridLayout(self)
        # addWidget(QWidget, row, column, rowSpan, columnSpan)
        grid.addWidget(self.load_button, 0, 0, 1, 1)
        grid.addWidget(self.edit, 1, 0, 1, 2)
        self.setLayout(grid)

        # bind the button clicked to action
        # newer connect style used with version 4.5 or higher
        self.load_button.clicked.connect(self.load_file)

    def load_file(self):
        """
        load the selected filename and display in QTextEdit
        """
        caption = 'Open file'
        # use current/working directory
        directory = './'
        filter_mask = "Python/Text files (*.py *.pyw *.txt)"
        filename = QFileDialog.getOpenFileName(self,
            caption, directory, filter_mask)[0]
        print(filename)  # test
        # use try/except to trap any errors
        fh = None
        try:
            fh = QFile(filename)
            # check if file is loaded
            if not fh.open(QIODevice.ReadOnly):
                raise IOError(str(fh.errorString()))
            stream = QTextStream(fh)
            # set the proper decoding
            stream.setCodec("UTF-8")
            # load the text to self.edit
            self.edit.setPlainText(stream.readAll())
            # optional show filename in title bar
            self.setWindowTitle(QFileInfo(filename).fileName())
        except (IOError, OSError) as e:
            QMessageBox.warning(self, "Load Error",
                    "Failed to load %s: %s" % (filename, e))
        finally:
            if fh is not None:
                fh.close()


app = QApplication([])
frame = MyFrame()
frame.show()
app.exec_()