def ModifyIssFiles()

in SetVersion.py [0:0]


def ModifyIssFiles(fileList, targetVersion):
    issFiles = [f for f in fileList if os.path.splitext(f)[-1] == ".iss"]
    for issFile in issFiles:
        print("Updating file ", issFile)
        with open(issFile, "r+") as f:
            fileData = f.read()
            f.seek(0)
            fileData = re.sub(r"(#define MyAppVersion).*", 
                r'\1 "{0}"'.format(targetVersion),
                fileData)
            f.write(fileData)