checking to see if diffFile is a submodule.

Is there a way to check to see if a diffFile is a submodule?

The repo that I'm getting my diff deltas from is bare so there's no working directory for Repository.lookup_submodule(path) or Repository.listall_submodules() to work with.

The main issue is when I try to get an added file via something like:

new_file = git_repo[delta.new_file.id]

I get the following key error.

Traceback (most recent call last):
  File "/Users/user/project/venv/lib/python3.7/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/Users/user/project/venv/lib/python3.7/site-packages/django/core/handlers/base.py", line 126, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/Users/user/project/venv/lib/python3.7/site-packages/django/core/handlers/base.py", line 124, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/Users/user/project/venv/lib/python3.7/site-packages/django/views/generic/base.py", line 68, in view
    return self.dispatch(request, *args, **kwargs)
  File "/Users/user/project/venv/lib/python3.7/site-packages/django/views/generic/base.py", line 88, in dispatch
    return handler(request, *args, **kwargs)
  File "/Users/user/project/repos/views.py", line 105, in get
    new_file = git_repo[delta.new_file.id]
  File "/Users/user/project/venv/lib/python3.7/site-packages/pygit2/repository.py", line 121, in __getitem__
    raise KeyError(key)
KeyError: ffeef8955335d0ec95f23c2fd75821672cf14bb9

If it's a submodule I don't need the contents. I just need to know that it's a submodule. Is there a general way to do this?

Start by reading the handling around delta.new_file.id and the Repository.lookup_submodule(path) and Repository.listall_submodules() APIs, especially for bare repositories. Check how a diff entry identifies a submodule without loading its contents. Done means documenting or exposing a reliable way to distinguish submodule entries before indexing the repository.