python os.rename(…) won't work !

Question

I am writing a Python function to change the extension of a list of files into another extension, like txt into rar, that\'s just an idle example. But I\'m getting an error

Answer 1

import os

def extChange(path,newExt,oldExt=""):
    if path.endswith != "\\" and path.endswith != "/":
        myPath = path + "\\"
    directory = os.listdir(myPath)
    for i in directory:
        x = myPath + i[:-4] + "." + newExt
        y = myPath + i
        if oldExt == "":
            os.rename(y,x)
        else:
            if i[-4:] == "." + oldExt:
                os.rename(y,x)

now call it:

extChange("C:/testfolder/","txt","lua") #this will change all .txt files in C:/testfolder to .lua files
extChange("C:/testfolder/","txt") #leaving the last parameter out will change all files in C:/testfolder to .txt