This is a semi-automated change based on python-rope/rope:

```bash
$ pname=raft
$ find -iname '*.py' -exec \
  sed -i 's/sys.path.append.*$/pass/' '{}' '+'
$ rm -rf alt_cuda_corr # confuses rope, recover later
$ prefix-python-modules . --prefix "$pname"
$ prefix-python-modules . --prefix "$pname" \
    --rename-external 'utils' "$pname".core.utils "**" \
    --rename-external 'update' "$pname".core.update "**" \
    --rename-external 'extractor' "$pname".core.extractor "**" \
    --rename-external 'corr' "$pname".core.corr "**"
$ git checkout -- alt_cuda_corr
```