home = "./FFCache/"
[download]

The current directory is not what you think. Change (for example, in your Perl script) the current directory to an absolute, known path.

Alternatively, from reading the Python program, you can give it the base directory as the first argument, so you might want to try that.

Also, you might want to replace

commands.getoutput('chmod -R 777 cachedata') </c>

with the native Python function calls instead of a (brittle) system call.