Error while trying to replace a opened csv file with the newone in my plugin

Question

My plugin does some basic geoprocessing functionalities and write the output as csv file. What i want is when i open some already writed output csv file in a writable mode and try to replace the same csv file for the newoutput, i got an error which is attached below. Code is also attached for reference.

def writeToFile(self, lsOfCities, filePath):
    fileCSV = open(filePath, "w")        

    for i in lsOfCities:
        fileCSV.write(i)
        fileCSV.write(",")
        fileCSV.write("\n")
    QMessageBox.information(self.dlg, "Number of Cities Near", str(len(lsOfCities)) + " cities are written to "+filePath)
    fileCSV.close()
    self.dlg.close()

I want my plugin to show a warning message instead of below error.

Answer 1

You need to use a try/except block:

def writeToFile(self, lsOfCities, filePath):
    try:
        fileCSV = open(filePath, "w")

        for i in lsOfCities:
            fileCSV.write(i)
            fileCSV.write(",")
            fileCSV.write("\n")
        QMessageBox.information(self.dlg, "Number of Cities Near", str(len(lsOfCities)) + " cities are written to "+filePath)
        fileCSV.close()
        self.dlg.close()
    except IOError:
        # Add your error reporting/handling code here