def METHOD_NAME(self):
    filetypes = [
        ("HTML Files", "*.htm *.html", "TEXT"),
        ("PDF Files", "*.pdf", "TEXT"),
        ("Windows Help Files", "*.chm"),
        ("Text Files", "*.txt", "TEXT"),
        ("All Files", "*")]
    path = self.path.get()
    if path:
        dir, base = os.path.split(path)
    else:
        base = None
        if sys.platform[:3] == 'win':
            dir = os.path.join(os.path.dirname(sys.executable), 'Doc')
            if not os.path.isdir(dir):
                dir = os.getcwd()
        else:
            dir = os.getcwd()
    opendialog = tkFileDialog.Open(parent=self, filetypes=filetypes)
    file = opendialog.show(initialdir=dir, initialfile=base)
    if file:
        self.path.set(file)