跳过QPixmap线

Question

我有以下代码：

def run(self):
        filename = QtGui.QFileDialog.getSaveFileName(self, "Save file", "", ".inp")
        if filename == "":
            pass
        elif filename != "":
            nfile = open(filename, 'w')
            self.pixmap1 = QtGui.QPixmap('yellow.jpg')
            self.canvas1.setPixmap(self.pixmap1)
            self.cursor.movePosition(self.cursor.Start, self.cursor.MoveAnchor)
            self.cursor.movePosition(self.cursor.End, self.cursor.KeepAnchor)
            text = self.cursor.selection()
            text1 = text.toPlainText()
            nfile.write(text1)
            nfile.close()
            fileInfo = QtCore.QFileInfo(filename)
            name = fileInfo.baseName()

            import os
            os.system("rungms {}.inp 13-64 {} {} {}.out".format(name, self.cores_val, self.clusters_val, name))

            from itertools import islice
            import sys

            with open("{}.out".format(name)) as searchfile:
                for line in searchfile:
                    if 'TERMINATED NORMALLY' in line:
                        self.pixmap1 = QtGui.QPixmap('green.jpg')
                        self.canvas1.setPixmap(self.pixmap1)
                    elif 'job aborted' in line:
                        self.pixmap1 = QtGui.QPixmap('red.jpg')
                        self.canvas1.setPixmap(self.pixmap1)
                    else:
                        pass
        else:
            pass

我的问题是保存文件后没有读取涉及QPixmap('yellow.jpg')的两行。但是，如果我在代码的第一行和第二行之间移动这两行（即在filename = QtGui ...之前），那么它们就可以工作。

有人可以向我解释为什么会这样吗？