this file probably need to be open'ed with os.open(path, os.O_CREAT | os.O_EXCL) to guarantee that full path does not
exist. This is to avoid a file creation race condition. something like:
```
     outfile = os.fdopen(os.open(os.path.join(directory, filename), os.O_CREAT | os.O_EXCL)., 'w')
```
Should get you a file object for that guy safely. 

If it can't a file there, it's going to raise an OSError. I would check to see if that get's handle up the
stack somewhere. We may need a finally clause to cleanup any partially extracted files in that case.