Error when "Cancel" while opening a file in PyQt4

pyqt4, python

Solution

Yes: simply check the return value from `getOpenFileName`. This method returns an empty `QString` if the user clicks Cancel. As empty `QString`s are considered false, you can check to see if the user chose a file instead of clicking Cancel by putting the last two lines of your `openFile` method in an `if openFileName:` statement:

    def openFile(self):
        openFileName = QtGui.QFileDialog.getOpenFileName(None, "Open File","/some/dir/","TXT(*.txt);;AllFiles(*.*)")
        if openFileName:
            openFile = open(openFileName,'r').read()
            self.plainTextEdit.appendPlainText(openFile)

Problem

I have a simple PyQt4 GUI where I have the user open a txt file that will display in the GUI's QPlainTextEdit widget. Here's the pseudo code: ``` class mainWindow(QtGui.QWidget): def __init__(self): super(mainWindow, self).__init__() self.layout = QtGui.QVBoxLayout() self.plain = QtGui.QPlainTextEdit() self.openButton = QtGui.QPushButton("OPEN") self.layout.addWidget(self.plain) self.layout.addWidget(self.openButton) self.openButton.clicked.connect(self.openFile) def openFile(self): openFileName = QtGui.QFileDialog.getOpenFileName(None, "Open File","/some/dir/","TXT(*.txt);;AllFiles(*.*)") openFile = open(openFileName,'r').read() self.plainTextEdit.appendPlainText(openFile) ``` So I click the "OPEN" button and the QFileDialog pops up, but if I hit the "CANCEL" button within the QFileDialog, I get this error: ``` IOError: [Errno 2] No such file or directory: PyQt4.QtCore.QString(u'') ``` I know as the programmer that this error can be easily ignored and does not impact the code's operation whatsoever, but the users do not know that. Is there a way to eliminate this error from printing in terminal?

Original source