This still seems confusing/unclear. I'd suggest something more like:
```python
def get_all_files(directory):
    """
    For each file in the directory, yield a 2-tuple of (file-name, directory-path)
    """
    for dirpath, dirnames, filenames in os.walk(directory):
        for filename in filenames:
            yield (filename, dirpath)

def get_dir_for_fname(directory, filename):
    """
    Returns the path to the first file found in the directory with the given name.
    If there is no file in the directory with the specified name, return None.
    """
    for fname, dirpath in get_all_files(directory):
        if fname == filename:
            return dirpath
    return None

fname = "course.xml"
dirpath = get_dir_for_fname(directory, fname)
if not dirpath:
    # return JsonResponse
# continue
```

It's longer, but it's much clearer. Also, if you move those two functions outside of the view function, they're reusable and the view is easier to unit test.